Green Design, Green Upkeep: Building and Maintaining Your Environmentally-Friendly Home

Residing in an energy efficient building not only lowers your utility bills, but can add an average of 14% to your home’s value, meaning it is not only good for the environment, but also beneficial for you as the homeowner. When setting out to build a green home, there are several factors to take into account, but the most important one to keep in mind is that a green home needs to be treated as such, from inception and throughout its lifetime.

The first, and perhaps most important, step in building a green home is a design conducive to environmentally favourable construction. A green home is much more than simply designing the living spaces, but must also account for the mechanical systems and materials used to qualify as a green construction. Once you have your design in place, you can move on to choosing which green materials will make your home as efficient as possible.

Sustainability is Key
Choosing sustainable products is one of the most important aspects of constructing a green home. You’ll want to make sure you select building materials that are certified as such by a specialist organisation and to research those materials in terms of eco-friendliness and stability in the long term. For the larger portion of the construction, you’ll need to procure sustainably forested timber, and perhaps to look into a roofing material that can be recycled or repurposed at the end of its life cycle.

For the interior of the home, there are many green products that are aesthetically as lovely as anything else on the market. From flooring and skirting boards to countertops and backsplash tiles, there are a multitude of sustainably produced, recycled or recyclable, and re-purposed materials to select from that will fit any style. With green building being so popular now, manufacturers are quick to disclose such properties and advertise themselves as appropriate for ecological construction.

Pay More Upfront
Energy efficiency is one of the main components to green building and you’ll want to take this into account in all aspects of the home, from windows to mechanical systems. High efficiency systems may cost more upfront, but will save you energy and money in the long term, eventually paying for themselves. Many of these systems will come with a guarantee, and the manufacturers will have already done the maths on your projected savings over the life of the home, so you’ll quickly be able to see how much you’ll save.

A Finished House Isn’t the End
Once you’ve completed a sustainable, green home, you have to keep in mind that environmentally-friendly maintenance must be part of the plan. Some of this maintenance should factor into the home design, especially in terms of landscaping. You’ll want to select plants and grasses that are native to the area, therefore, requiring less water and fertilisation. Additionally, you’ll want to explore some eco-friendly cleaning solutions, as many cleaners use harsh toxic chemicals that can be damaging to the environment.

Committing to a home that is environmentally responsible is one that will last a lifetime. The process may be challenging, but keeping your goals and reasons for undertaking such a project is key. The financial commitment upfront may save you some money in the long run, but it will take more effort and money to bring your green home dreams to life, and to maintain it thereafter.

Zero-Energy
Designing and maintaining a zero-energy home takes a lot of thought and consideration as well as a know-how on the best way to get the most out of the technology involved. Technology is rapidly changing which means that the trends of today are often out of favour a few years later. Government subsidies and schemes can play a big part of how well companies market their preferred product in terms of benefits, efficiency and cost so it is important to do your research.

The bulk of the battle to become zero-energy often lies with simple aspects such as making sure the building is well insulated and air-tight. Thought should also be given to the orientation of the building in relation to the sun; as natural light can help reduce energy bills in terms of lighting, heating and cooling. Using some form of brise-soleil (an architectural feature of a building that reduces heat gain within that building by deflecting sunlight) can prevent overheating in the summer; whilst still gaining the warmth and light from the low winter sun. Trees that provide shade can also help.

Moving onto the technology side of things, there are many routes available that each have their benefits and drawbacks. Where energy is sourced from is perhaps the main hurdle to overcome. Whilst solar panels are one of the more well-known ways of reducing energy costs, other alternatives to look at include Micro CHP boilers, air source and ground source heat pumps. Upgrading appliances to more energy efficient ones is often overlooked. Mechanical Ventilation Heat Recovery can remove stale air whilst retaining some of the heat which transfers to the fresh air entering the building which reduces the amount of heating required.

Team Trip to Kingspan to Learn about Timber Frame Housing

It is always very productive and a change of scene; to get the Building Tectonics team out of the office together to learn more about particular areas that we work on.  So, on Thursday 14th March we all went on a trip to Kingspan Potton, based in Great Gransden, Bedfordshire who specialise in fabricated timber frame housing.

The walls, floors and roof of the houses are fabricated in large panels in their factory and are then taken to site and bolted together to construct a house (or other types of buildings).  Although there are several companies who already work in this area; Kingspan have moved away from the mass housing market and instead of supplying the larger house builders, now just supply one or two units to small developers or even one-off houses.

On arrival the BTL team were greeted in the meeting room by the National Sales Manager; who gave a presentation about the different products they produce and then showed them around the factory where they are made. They saw how the process works from start to finish; from when the wood comes into the factory to when it leaves on the back of the lorry.  Following this, they drove 15 minutes away to the Potton Self-Build Show Centre in Little Paxton, near St Neots where they have 5 show-houses. The team had the opportunity to look around the show-houses; which showed them the different materials that Kingspan manufacture and the different structures that they are capable of producing.

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Kingspan can help with the design of any house and have a pattern book of designs you can choose from; but obviously being an Architectural Practice, we already do the design for our clients.  However, Kingspan can take our bespoke design plans and prepare “shop drawings” showing the panels so that they can then be fabricated in their factory. It was very interesting for the BTL team to know all about the process and the types of systems available; for those occasions when a client wishes to have a timber frame house.

There are alternative systems available from other timber frame fabricators: –

Open Panel Systems
The majority of timber frame companies use an open-panel system for the internal loadbearing of the cavity wall.  These are made in a factory from a softwood timber frame covered with a structural sheet material such as plywood or oriented strand board (OSB) and fixed into a structure on-site.  They have a waterproof membrane on the outside and are left open on the inside.  The windows and door frames are fixed on-site and when the house is watertight; the electrical and plumbing casing is installed and the insulation put in place finished off with a vapour-proof barrier and plasterboard.

Closed and Advanced Panels
These systems are used by most of the Scandinavian frame companies and are delivered fully furnished and insulated, with the services in and the windows and doors already fixed – with the advantage that it is an airtight structure that needs minimal on-site work. However, it does mean decisions need to be made early on in the design about services and outlets.

Green Oak Frame
This is the most traditional timber-frame building method and is often referred to as exposed timber frame. The oak is often jointed using mortise and tenon joints, draw-pegged with tapered oak pegs and then integrally braced with curved oak bends jointed into the frame.  Insulating panels are then infilled into the massive oak skeleton and it is made waterproof using a system of perimeter trims and water bars; before being rendered on the outside, leaving the timbers exposed.

SIP Systems
Structural insulated panels (SIPs) are high-performance building panels used in floors, walls, and roofs and are typically made by encasing a core of rigid foam plastic insulation between two structural skins of OSB, but other skin material can also be used.  The panels are manufactured under factory-controlled conditions and can be custom designed for each home.  SIPs are fixed to the outside of the timber frame, so the entire frame can be exposed in the interior or covered up, depending on the look you want to achieve.

Kingspan are first and foremost an insulation company and therefore, have naturally moved toward the highly insulated end of the market.  Timber frame housing can be extremely well insulated and this form of construction lends itself to the addition of a lot of insulation without making the walls unduly thick (unlike brick and block walls).  However, the really interesting development is the SIP technique as these panels can achieve incredible levels of insulation and therefore, are often found in zero energy projects where no heating is required; other than the heat that is created by simply inhabiting the house (possibly with the addition of some solar heating).

Building Tectonics have designed a couple of very low energy houses and are greatly interested in this area. SIP panels also offer really low air infiltration so therefore, help reduce heating bills and increase comfort as they avoid drafts and cold spots.  They can be very strong and rigid and can be used in floors and roofs; which is a real game changer in the construction of houses, but the building industry has generally not embraced this new technology.  Houses built like this can be erected on-site superfast incorporating all the services and the standard of finish can also be superior.

As a practice we would like very much to use this technology wherever we can; but the question is whether our clients will choose something brave and new.  The major practical difficulty is using prefabrication techniques for extending existing buildings, which is where most of our work lies. Ironically, the big problem would be bolting something so perfectly made (1 or 2 mm accuracy) on the side of an existing building where the building tolerances can often be measured on several centimetres. What we need are clients who can see the benefits of such new techniques and we stand ready to help in any such project should it arise.

The Tiny House Movement: Ecocapsules

Following the tiny house movement, which is a movement in which people are downsizing the space in which they live. The main reason for choosing this lifestyle is financial gain. What they’re not spending on their home, they have to spend elsewhere.

A Slovakian architectural company called Nice Architects Studio have taken this idea and created what seems to be one of the next eco friendly tiny houses.

Their product, the eco capsule, could become the next big thing in the tiny house movement. It’s 86 square feet of eco friendly space, off the electrical grid, and it’s also portable. Each capsule has solar panels across the roof of the egg shaped exterior, and a retractable wind turbine so you can get power in all kinds of weather. If you are in very poor conditions and need backup power there is a high capacity battery built into the structure which you can use, so that hopefully you’ll never be without power. The design of the capsule allows rainwater to be caught on the surface, and run down the side into a space at the bottom where there are filtration systems in place so that the fresh water is safe to use, hot or cold.

They would also fit into a ship container, and so could be taken overseas if the owner were a keen traveller, or a scientist, explorer or anything which required being out of the country.

These will be available to pre-order at the end of 2015 with shipping starting in early 2016.

Written by Jade Turney – Building Tectonics

Renewable Heat Incentive.

The Renewable Heat Incentive (RHI) is the first government funded scheme of its type in the world, in the sense that it is the first long-term financial support programme for renewable heat. It’s an incentive from the government which is designed to reward people who use renewable energy to heat their buildings. This scheme was put in place to attempt to help us reach our goal of around 12% of heating coming from renewable energies.

  1. There are two phases of the scheme for this incentive: The first phase is for the non-domestic sector; the industrial, commercial, public sector and community organisations.AND
  2. One which is for residential dwellings. This one is expected to go live in 2014. The Renewable Heat Incentive will offer regular tariff payments for 7 years to people who choose to use certain technologies to heat their homes with. The amount of money which is paid depends on what technology is used to heat their homes, such as solar thermal water heating panels, heat pumps and biomass boilers (which use wood pellets, chips or logs).

Some of the technology which is eligible includes:

  • Air to water heat pumps.
  • Biomass – only boilers and biomass pellet stoves with back boilers.
  • Ground and water source heat pumps.
  • Flat plate and evacuated tube solar thermal panels.

The RHI is similar to the Feed-In Tariffs, which is a financial support scheme for people who create their own electricity. However, there are some massive differences between the two including:

  • This will be paid for by the Treasury rather than energy users.
  • There is no ‘National Grid for Heat’ so importing and exporting heat is irrelevant.
  • It will be introduced in phases, residential schemes will not be eligible until Phase 2, in 2014.

Written by Jade Turney – Building Tectonics Ltd.

Photo-voltaic Panels

Photovoltaic panels are a highly efficient way of lowering your electricity bills. If you had these installed, you would be generating your own electricity, therefore you would not need to pay for as much energy.

In fact, you could be getting paid for producing your own electricity! If you join the scheme, your energy provider pays you for every unit of electricity which you produce, and any electricity you produce but don’t use yourself can be sold back to the national grid.

Photovoltaic basically means converting light to electricity, with “photo” meaning light and “voltaic” meaning electricity. So I guess you could say that they do what is said on the tin, so to speak.

Back in the 1950’s, this technology was almost exclusively used for powering electrical circuits in satellites, but the range of uses for solar energy has grown considerably now, for example we now use it for calculators, electric vehicle charging stations. On a bright and sunny day, the sun can produce up to 1000 watts of energy per square meter of the surface of the planet, if we could harness this, we could easily power our homes and offices for free.

Photovoltaic cells are made of special materials, which are known as semiconductors, such as silicon which is currently the most commonly used. The flow of electrons from sunlight creates the current, and by placing, metal contacts either side of the photovoltaic cell, we can draw that current off of the panel for external use, powering things which require electrical energy. This current, together with the cells voltage defines the wattage which the  solar cell can produce.The panels don’t necessarily need direct sunlight, therefore they would work on cloudy days as well as sunny ones.

Architects are beginning to suggest using these sorts of technologies when designing projects for clients, as what they would pay for the installation now would be saved many times over as time goes on.

Written by Jade Turney – Building Tectonics Ltd.

Ground source heat pumps

Ground Source Heat Pumps (GSHP) use pipes which are buried underground to extract the constant heat which is generated in the ground, hence the name “ground source” heat pumps.

A GSHP pumps a mix of water and anti-freeze around a loop of piping, which is called a ground loop which is buried wherever you have decided to have the system installed. The ground stays at a reasonably constant temperature under the surface, so the pump will be effective throughout the year, including in the middle of winter.  The heat in the ground is then absorbed by the passing liquid which then passes through a heat exchanger into the heat pump.

The length of the pipe is determined based upon two main factors; the size of your home, and the amount of heat which you need. It goes without saying that longer loops can draw in more heat due to a larger area from which to absorb, but they also need more space to be buried into. If you have a limited amount of space available, you can always have a borehole drilled instead.

After passing through the heat exchanger the liquid is cool again, so it goes around the loop again, picking up more heat on the way. This is a continuous process, which goes on for as long as the heating is required. The loop is usually laid flat or coiled in trenches which are dug to a depth of around two metres, but if there isn’t enough room for this, you can have a vertical loop instead, this can go up to around 100 metres deep for a typical domestic residence.

GSHPs don’t need fuel, just a little electricity to keep the pump going, but this is a very small amount of electricity compared to an electric heating system. For every unit of electricity used for the pump, three to four units of heat are returned, so it is very efficient. This type of renewable energy can heat your home and give you hot water as well as lowering your fuel bills and your homes carbon emissions, but by how much depends on what fuel you are replacing.

If you are thinking about getting this system installed for your home, it is imperative that your home is properly insulated and the building envelope is completely sealed. This is because the ground source heat pump produces heat at a lower temperature than traditional boilers. They can perform better with underfloor heating, or warm air systems because lower water temperatures are required of it. It also doesn’t require much attention in the way of maintenance, it’s called ‘fit and forget’ technology.

Getting a ground source heat pump installed could also provide you with additional income through the governments scheme ‘Renewable Heat Incentive’ (RHI).

Written by Jade Turney – Building Tectonics Ltd.

Borehole Thermal Energy Storage

Borehole Thermal Energy Storage (or BTES) is basically an underground structure, usually quite large, which is used to store large amounts of solar heat that was collected in the summer, for use in the winter time. You could think of it as being a massive underground heat exchanger.

Wherever boreholes can be drilled, these systems can be constructed. The system is usually composed of anywhere from one to a few hundred vertical boreholes. Warm temperature seasonal heat stores can be created using borehole fields to store surplus heat which is captured in the summer to actively raise the temperature of large thermal banks of soil, so that heat can be extracted more easily (and more cheaply) during the winter.

A ground source heat pump will be used in the winter, extracting the warmth from the thermal bank (the soil which absorbed the summer heat) to provide heating to a space via underfloor heating. Boreholes are filled with grout or water, dependent on the geological conditions, and they usually have a life expectancy in excess of 100 years. They don’t impair the use of the land in any way, as they can exist underneath buildings, agricultural fields and car parks.

In terms of heat storage, the flow of heat transport liquid in the summer comes from the center of the structure, and travels to the outer edges, by doing it this way the heat is transferred through conduction to the surrounding soil. When winter comes along, the flow direction is reversed, so the liquid flows from the outer edge of the system to the center, drawing in heat. By traveling in the reverse direction, the heat which was stored in the soil is then transferred back to the liquid running through the system.

The ground heat exchanger for BTES systems is designed and operated in such a way, so that the heat is stored or abstracted, seasonally whereas conventional GSHP systems are designed to simply dissipate heat or cold into the subsurface. BTES essentially uses the Earth as a giant thermal battery as opposed to a radiator.

This system typically involves design and operation of the Ground Heat Exchanger (GHX) in a manner so that the heat is sequentially built up in, or abstracted from a cylindrical column of rock or soil. This system usually consists of a number of boreholes resembling dry wells, and after drilling this hole, a plastic “U” pipe is inserted down the borehole. To provide a good thermal contact with the surrounding soil, the borehole is filled with a high thermal conductivity grouting material.

When solar heated water is available to be stored, it is then pumped into the center of the BTES field and through the U pipes. Heat is transferred to surrounding soil and rock, and the water gradually cools as it reaches the edge of the structure and returns to the energy center.

Written by Jade Turney – Building Tectonics Ltd.

Solar water panels.

There is a technology which is becoming more and more readily available, that can help out with your heating bills. You may (or may not) have heard about these before, they’re called ‘Solar Water Heating Panels’.

These panels are placed on the south-facing side of your roof, or if you have a flat roof, they are placed on a frame at a 20-50 degree angle to make the most of the suns rays, which are then used to heat stored water in a tank. These systems are so useful because they can generate around a third of your hot water needs throughout the year. Here’s the best bit though – you wouldn’t need to continuously pay for this water to be heated! Some homeowners have been known to reduce their annual energy bills by anything between 30-70%.

The savings which are made depends on the size of your property, the size of the heating installation and the amount of sunlight in your area. Your panel would be doing most of the heating, the only thing you would have to pay for would be the cost of running the small electrical pump, and the occasional running of the backup immersion heater or boiler you may have chosen to add to the system to heat the water further, or as a backup for days when there isn’t so much sunlight to power the system. When compared to using a conventional heater alone, this is a very small margin of cost. Sure, the initial cost of installing the system is a lot higher than getting a conventional heating system fitted, but you would definitely get this money back through the savings you will make on your heating bills.

These panels also reduce your carbon footprint as well as your bills as they are a sustainable and renewable source of energy. You can use a boiler, or an immersion heater as a backup for when there isn’t so much sunlight to power the system, or to heat the water coming through the system even further. Even though this would use electricity, it would be a substantial amount lower than current overall heating bills.

There are two main types of solar water heating panels – flat plate panels and evacuated tubes. Evacuated tube panels are much more efficient than the flat plate panels because even though they are smaller, they can create the same amount of hot water. You could also add a drain-back system to these panels, which would then drain the water from the panel when it is switched off to prevent it from boiling or freezing whilst inside the panel.

Solar water heating panels can provide you with around a third of your hot water needs whilst saving  you between £55 (if you have gas-powered central heating) and £80 (if you have electric central heating) a year on heating bills. The maintenance costs for this system are relatively low and most systems come with a minimum of 5-10 years guarantee, but they usually need very little maintenance. These panels can be very heavy, so consequently, your roof needs to be strong enough to hold the weight of them.

Written by Jade Turney – Building Tectonics Ltd.

Save money with rain water harvesting.

Rainwater harvesting is exactly that – harvesting, or collecting rainwater as it runs off of impervious surfaces, and then storing it to use any time you want to. Traditionally, this involves collecting water from the roof which is directed to gutters, then it is channelled by these gutters, into downspouts which then direct the water into some sort of container. Rainwater collection has been around for such a long time, it just lost a bit of popularity over time, but as we move into an environmentally friendly age, it seems to be regaining in popularity.

The art of rainwater collection was forgotten for a very long time, but it’s making a bit of a comeback, with this environmentally friendly age we are moving into. For example, due to the Green Building Movement, you may begin to see more rainwater harvesting systems being implemented in America.

A rainwater collection system can be as simple as collecting rain in a water tight barrel, or something a tad more elaborate, like harvesting the rainwater into large cisterns to supply your household with their water supply.

Mind you, the use of rainwater collection is not to be confused with the use of grey water. Grey water is that water which is not dirty but it’s also not completely clean. It’s the leftover water from your bath or shower and your washing machine water (when it’s been on a rinse cycle), the water which is neither considered dirty, nor completely clean. This water can however also be collected and used on the garden, provided that not a lot of soap/detergent has been used. I’ll talk more about grey water soon in another blog.

There are many different benefits you could get from rainwater collection, including the obvious one – it’s free.

Harvesting your own rainwater gives you the freedom to manage your own water supply, you have complete control over it. Not to mention that you’d be helping to conserve water around the world, whilst promoting self sufficiency. Your garden would definitely benefit if you got into the habit of collecting rainwater too, as it’s better than the chlorinated, treated water from the taps – it is 100% natural after all! Implementing this system doesn’t have to be expensive at all, and it’s easy to retrofit to a building. These systems can also be very flexible, allowing to change their size, or move them if and when necessary.

All you need to do to take advantage of this resource is to catch the (free) water falling onto your roof, store it, and use it. That’s all there is to it. By implementing this simple system into your home, you can replace most, if not all of your water needs, saving you money!

You could achieve all of this, by the simple act of putting a bucket outside to collect water, and using it to wash your car, or your pet instead of the taps. It’s easy really.

Written by Jade Turney – Building Tectonics Ltd.

Heat recovery systems

If you’re thinking about building an energy efficient home, then a heat recovery system could help you to meet some of the heating needs of your home, as well as helping with distributing the heat. Many of these systems also come with air filters, which makes them helpful in preventing potential allergens entering the house (which is a positive for sufferers of asthma!).

Heat recovery ventilation basically extracts the warm, moist air from inside the home, which would usually be lost through opening doors or windows, and passes it through a ‘heat exchanger’ (a system hidden away in the loft, or somewhere convenient) through a pipe or tube, and fresh air is simultaneously drawn in from outside and passed through this same box, where the pipes or tubes are placed fairly closely together. Through the pipes being in such close proximity, the heat is transferred from the extracting pipe, to the pipe with the fresh air. The extracted air never comes into direct contact with any incoming fresh air. This is why it is called ‘heat recovery’, it is recovering the heat which would otherwise be leaving the property.

You could think of it a bit like when we hold a cup of tea, the heat from the tea is transferred through the cup to our hands.

Written by Jade Turney – Building Tectonics Ltd.