We will design, supply and erect the bespoke Eco-frame for your project – these timber frames are top specification designed specifically for a low energy house.
To meet standard UK building regulations, timber frames can be as little as 140mm in thickness, filled with light-weight fibreglass. We would never supply a house of this poor quality – the light-weight insulation would make the house suffer from large temperature fluctuations - overheating in the summer and too cold in the winter, whilst the thin 140mm walls mean the insulation properties will be poor resulting in a great amount of heat loss.
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| Typical 140mm timber filled with light-weight rockwool insulation. | Concrete block wall with 50mm celotex insulation. | Touchwood I beam wall – a superior 300mm packed solid with Warmcel insulation. |
Our timber frames are a substantially different product from this light-weight construction – our walls being 300mm thick and packed solid with injected Warmcel insulation to provide a comparatively heavy-weight structure, super insulated to produce a steady state internal temperature. This provides a wonderful warm living environment that only a heavy weight timber frame can achieve.
Pre-Cut Method
Our frames are completely designed in house on 3D CAD programs so that all the timber components can then be factory cut by computer controlled saw for perfect-fit accuracy.
This advanced concept results in a product which is very quick to install on site, as opposed to a carpenter working on site from architect's drawings and cutting each piece of timber as he goes. Our method is fast, accurate and provides the exact house design that you desire. Using Google Sketch-up we can send you the house design in 3D as it progresses so that you can make adjustments to achieve exactly the home you wish for. The timber frame above shows the design for a recent project in Hampshire.
With the finished construction below:
Timber frames can have any external appearance from render, boarding or even a brick skin – all of these will have no effect on the massive thermal advantage achieved by building with thick timber frame walls.
Technical Design Aspects
Solar Gain
When commencing a new project the first thing to think about is solar gain in the winter – during the cold winter months we wish to gain as much free heat from the sun as possible through the glazing, so it is important to have the house facing south, with the correct proportion of glazed area. This solar gained heat is calculated in the PHPP software as a heat input to keep the heat requirements of the build within the passivhaus specification. With a house this well insulated and air-tight, heat loss is at an absolute minimum, such that winter heat gained through the windows, and even heat given off by lighting, cooking and body heat all go towards keeping the internal temperature stable and comfortable. In the event of too much heat in the summer we always design in an automatically opening roof light which will release any excess heat in the summer months.
Heat Recovery Ventilation
When creating an air-tight house it is vital to control the ventilation by installing a Heat Recovery Ventilation unit. These are designed to remove stale air from kitchens / bathrooms, and replace it with fresh air from outside, which is preheated by the stale air. This results in the air being fresh without losing the heat within the air. Of course in the summer the windows could be left open to provide fresh air, but in the cold winter months this method would lose too much heat (energy) from the building.
It is vital to invest in a top of the range, extremely efficient unit with rigid duct work to make the system effective. There are quite a range of cheap, poor quality units on the market, ones we would never install on our projects. We design, supply and install PAUL HRV units in our builds, which have rigid steel ductwork threaded through holes pre-cut in the timber frame to allow for rapid install.
The PAUL HRV unit we use has an efficiency of 93%, some units are only 75% efficient meaning every air change to the build, 25% of the heat in the air will be lost.
The design of a unit it vital, with air flows to each area of the house needing careful design, and the correct outlets to ensure no regions in a room have no air movement. Our PAUL units also allow heat to be delivered to the house via a heater installed in the ducts which can be water based (from the thermal store) or electric. Our resident HRV expert Dr Williams designs our systems, and advises during install.
Foundations, Windows and Doors
To complement the super insulated timber frame we would also offer our Passivhaus foundation system. This is a great advantage over typical strip foundations since the entire foundation structure is thermally separated from the ground – so no heat is lost to ground. The system also uses much less concrete than strip foundations and can be completely finished within 5 working days – and that’s from an untouched site. Please see the foundation system page for more information.
Using our Passivhaus standard windows and doors is also highly recommended, these are some of the best on the market being triple glazed, with U values down to 0.79. We always use these on our own developments since the insulation properties and general build quality is stunning.
Please see the passivhaus windows and doors section for more information.
The Client - Touchwood Process
Often clients approach us when they have obtained planning permission on their plot - we can then use the submitted plans as a starting point for the design, or other times we can assist with the planning application.
To begin the process we will have a meeting to discuss the design and go through the various options available, to create the exact home you require. When the initial ideas are in place our designer will work on creating a 3D CAD model of the house which when complete we can export into Google sketch-up format allowing direct viewing on a clients ’ own PC.
This way clients’ can view the house in 3D at home and see exactly how the design will look. This is a great advantage, allowing plenty of time to think of modifications that may improve the design still further, modifications which are easy to implement at this stage. Typically there will be a few alterations to get the design exactly how you would like as new ideas come up.
The build methods we use open up many exciting design options - long spans creating large open spaces or curved roofs built with Glulam beams to create an inspiring contemporary house. Alternatively more traditional cottage type designs are possible, but all have the theme of minimal energy use.
When you are happy with the design the process is signed off and the house will go into production taking around 4-6 weeks. Our timber frame elements are then all precision cut in the factory on computer controlled machinery for perfect fit joints designed for simple and quick assembly on site.
This frame along with passivhaus standard windows, doors and cladding (if required) will then be delivered to site ready for quick on site construction. Having the whole frame in one delivery minimises transport costs, eliminates the need for a crane (often not possible on small sites) and provides a perfect fit build – these are just some of the advantages we have found our system has over factory panelised frame built houses.
Our team will then be on site to receive the delivery, and begin putting the structure up – a process that will take around 4-5 weeks. Once completed, the structure will be clad with racking board to form a strong, air-tight structure ready for your other tradesman to begin.