Designing a house extension involves thoughtful consideration of both the aesthetics and functionality, with materials playing a pivotal role in the overall outcome. The choice of materials can singnificantly influence the extension’s cost, appearance, durability and environmental impact.
Common materials include brick and stone for a classic look, glass for modern, light-filled spaces and timber for a warm, natural feel. Integrating these materials harmoniously with the existing structure ensures a cohesive design.
Additionally, selecting sustainable and energy efficient materials can enhance the extension’s performance and reduce long-term costs. A well-designed extension seamlessly blends with the original home while enhancing its character and usability.
House Extension Design
What is a SIP panel extension?
Structural insulated panels (SIPs) are a modern and efficient method of construction, utilising off-site manufacture, and suitable for a variety of uses, ranging from small ancillary buildings through to residential, commercial, leisure and public sector construction projects. SIP panels consist of two sheets of OSB3 (oriented standard boards) adhered to a sheet of rigid foam insulation. These panels are compressed together under high pressure to form a structurally strong panel, set with specialist adhesive.
SIPs are one of the most sustainable and efficient construction materials, both during manufacture and construction, creating energy-efficient buildings suitable for a variety of uses, including home extensions.
Roof Specification
Our roof specification comprises of 18mm WBP (weather & boil proof) plywood - an exterior grade so long as it is treated with a preservative where the glue line will not break down when subjected to adverse weather conditions. For insulation we use an aluminium foil backed insulation (reflective insulation) that reflects heat and prevents it from moving to the other side of the insulation material. An air flow void is enables ventilation that stops warm air condensing on cold surfaces, as condensation encourages rot and mould growth - This is all mounted on 150mm x 44mm roof rafters. We use plasterboard for the interior wall and skim plaster for a superior finish. We use a roofing felt system as a secondary layer of protection that helps prevent moisture from infiltrating your roofing system.
Cavity Tray Specification
The purpose of a cavity tray is to prevent dampness from permeating the internal skin of a wall, where the brickwork rises above a roof slop. It keeps the wall below dry by draining rainwater back through the outer leaf.
Foundation Floor / Cavity Wall
Our foundation floor sits upon the hardcore over ground, where we layer building sand and a damp proof membrane before adding 50mm insulation. We then pour concrete screed and finish with a wood floor or tiles.
After we pump concrete into the foundations, the bricklaying team constructs the sub blockwork up to damp course level. This is where we pour the concrete floor screed and the cavity walls are built up to roof joist height.
To start the build process, we there may require demolition to make way of the new extension, then this that we’ll then remove from site. After, we’ll excavate the foundations, plan drainage routes and lay the new pipes.
Next, we’ll pump concrete into the foundations. And bricklaying team will then build the sub blockwork up to damp course level, install 50mm insulation and the damp proof membrane. We’ll then pour the concrete floor screed and the cavity walls are built up to roof joist height.
We then support the upper internal wall, so the below wall can be taken down and knock through from existing house to the new extension is then opened for the bottom floor
Next The fitting of steels and pad stones to the engineers’ instructions are done and our carpenters fit a timber flat roof with falls and openings for any skylights. The roof is then insulated and made watertight. New cavity trays are inputted to protect water ingress and leaks above the extension and the plumber fixes all internal pipe work.
The electrician will then fix all electric wiring.
The bi-folding doors and skylights are fitted to make the building watertight and secure. We then Plasterboard the ceiling, dot and dab the internal walls and finish it with plaster.
Decoration is done via our advanced spray guns to walls and ceiling either white or your chosen colour. Carpenters then fit skirtings and carry out any carpentry work needed. The floor is tiled, and the new kitchen is fitted.
All second fix electrical and plumbing work is added and the outside is rendered and painted white, new fascia’s and soffits with guttering are also fitted. We give the whole extension a professional clean and get rid of any rubbish
Finally, we handover your brand new home extension with all necessary certificates.
Making you happy is the most importance thing to us here at EX10, so we’ll continue to speak with you about your home extension every step of the way.