The modular nature of our designs helps reduce costs and simplify construction. Many different building systems could be used, but we are currently using Structural Insulated Panels known as SIPs.
The big advantages of SIPs are:
Costs are reduced and efficiency increased because much of the material handling and construction is done out of the weather at the fabricators. Once the components are delivered, the basic structure can be erected in a matter of days. The windows and doors can be installed, the cladding and roofing added then the inside can be fitted out.
We started using SIPs panels from the US where they were invented. We have an existing working relationship with a manufacturer resulting from a project with the Swinomish Tribal Nation. We are now using the same system in the UK.
THE GREEN BIT
The high level of insulation and the airtight nature of SIPs structures make them very energy efficient.
A living roof minimises the ecological footprint, reduces rainwater run-off and provides a safe habitat for insects and birds. If you are building in an area prone to fires then using a succulent sedum can be excellent protection.
A LANDHOUSE always aims for the highest BREEM or LEED Assessment within the budget and geographical restrictions and is constantly seeking out the latest technology to suit the site.
THE TECHNICAL BIT
Our 1,400 square foot Swinomish layout proved very energy efficient when we ran it through the EcoTope computer modelling software, and some of the results influenced the final design and specification. Link to the EcoTope Report. Interestingly the green roof, has a slight cooling effect in hot weather and absorbs the rain and sun which prolongs the life of the roofing material.
Underneath the green roof is a certified waterproof membrane, designed and tested specifically for this type of application, which conforms to the German FLL standard - the toughest waterproofing test in Europe.
A typical extensive warm roof construction (from the bottom up) consists of: A structural layer, a vapour control layer, thermal insulation, waterproof membrane, a growing medium and finally the planting.
There are many different options for the roof, but the green layer is most often sedum based and can be pre-grown on special matting which is matured off-site, rolled up, then unrolled onto the substrate to create an instant green roof. In Germany, they have installed more than 80 million square metres of green roof which continues to do an excellent and sustainable job.
Some useful websites.