Is sustainable building construction more expensive?
Yes and no.
The up-front cost of sustainable materials and technology can be more expensive in the construction stage, but the running costs of the building over the rest of it's lifetime will be significantly reduced.
The lifetime of a building is typically described as 30 years because that's how long most product warranties last - obviously buildings last a lot longer. Generally the construction cost is 20-40% of the lifetime cost, leaving 60-80% for running and maintaining the building - so using sustainable strategies can save you a lot of money, they will give you a buffer against the likely rising cost of energy in the future and they are better for the environment.
Also, you don't have to go all out sustainable! We can tailor a strategy to meet your aspirations and budget. We can always build in the infrastructure for you to add sustainable technology at a later date.
What is Passivhaus?
Passivhaus has been developed by the Passivhaus Institute in Germany. It takes all the principles of sustainable design and using a points system allows the owner to certify their home through an exacting quality assurance process.
Passivhaus is much better for the environment, but harder on you wallet at construction stage. Typically a Passivhaus is 10-20% more expensive to build, due to the innovative of this standard. However, over the lifetime of the house can make up and exceed this extra cost due to it's energy performance. Another benefit is the quality of the building workmanship has to be higher, to pass the air-tightness tests.
Passivhaus Trust website for more information.
We fully believe in Passivhaus, but it is not for the faint of heart or right for every project. An alternative excellent, but less demanding standard is set by the AECB...
What is sustainable design?
Sustainable design concerns the materials we use, how they are sourced and how the building is put together. The five key areas are:
1. Timber construction reduces industrial emissions and is one of our biggest opportunities for long-term carbon storage.
2. Insulation in housing should be 300mm deep and wrap the heated part of the building. Critical detailing at junctions is essential so as not to undermine this through heat loss.
3. Air-tightness improves robustness against moisture, improves the effectiveness of a ventilation strategy, helps fire safety, and reduces noise transmission.
4. Ventilation should use both the opening windows for purge ventilation and summer fresh air, and mechanical ventilation with heat recovery (MVHR) for the background ventilation the rest of the time. The MVHR creates filtered fresh air to all rooms, removal of moisture from cooking, washing and drying clothes.
5. Triple-glazing improves against heat loss, along with the size and orientation of windows.
What does Evergreen Building Design do for you?
We help you design new buildings or refurbish existing ones. We follow the RIBA Stages of Work from defining the brief to completing construction of the building. We can also help with feasibility studies, to see if a project is worth your time undertaking.
Most projects need planning and building control approval. We do all the drawings and paper work that you need and handle any communication with the Local Planning Authority on your behalf.
You will require other consultants, such as structural engineers, mechanical and electrical engineers, timber frame specialists, ... and we will coordinate with them.
We work using 3D software to help you visualise your project, which makes it much easier to understand the project than 2D floor plans.
We have a network of local builders and manufacturers who specialise in sustainable building construction who we can put you in touch with.
Will I need Planning Approval?
Some projects can be undertaken without Planning Permission and these fall under Permitted Development Rights. The Planning Portal is a good place to start to get an idea of whether your project might fit the criteria.
Of course, we are here to guide you and we would always recommend getting in touch with the Local Planning Authority to ensure you don't start a project without getting the necessary permissions. Even if you don't need Planning Permission, you are likely to require Building Regulation drawings, to satisfy the Building Control Officer that your project is constructed to safe and correct standards.
The AECB Standard as an easier alternative to Passivhaus
The Association for Environment Conscious Building (AECB) uses the same assessment methodology as Passivhaus, but sets slightly less demanding environmental targets. It is still no slouch and a massive improvement from the basic Building Regulations.
The construction cost uplift is typically 5-10% depending on the technologies and materials used. Like Passivhaus, over the lifetime of the building it can make up and exceed this extra cost due to it's energy performance, and the quality of the building workmanship has to be higher, to pass the air-tightness tests.
AECB website has lots of resources if you are interested and of course feel free to give us a call if you wish to find out more.