To discuss your project give us a call on 01392 861763

Sustainable Building Forum

The place to share best practice advice about all things sustainable building. Use the search icon to find the topic you’re interested in or register as a member to comment on topics and ask your own questions.

Clear all

What type of roof construction should you use on your extension?

Chris Brookman
Member Admin

Again, as with the walls, there are two main types of roof. Pitched roofs (pitch greater than 15 degree angle) or flat roofs (pitch less than 15 degrees)and which you use depends on the constraints of your project and probably the type of roof the existing building has. 

The options are rather more limited on roofs as they are almost always timber so either way, we’d suggest using solid timbers and insulation between and on top of the rafters. Pitched roofs tend to be the default and would be covered with tiles or slate. Flat roofs would tend to be used on buildings that do not have the height for a pitched roof or are looking for a modern box type appearance.

To see what we’d suggest click the relevant link below:-

Detail for pitched roofs - click here

Pitched roof specification - click here

Detail for flat roof - click here

Flat roof specification - click here

Topic starter Posted : 09/03/2021 6:06 pm

CPD Training

We offer CPD training for architects practices across Devon and Cornwall.

Software Modelling

We offer dynamic heat and moisture modelling as well as condensation risk analyses.

Building Plan Review

If you have some plans and would like our opinion on which materials would be the best for you, contact us.


Back to Earth is a natural building material supplier. We're not your typical builders'​ merchant though and instead work closely with our clients during the planning, designing and building phases of projects.

© 2018 Back to Earth