On site with our energy efficient new-build house in Balham

Written by: Mantas Gaigalas Project Architect

On site at our Balham Project 

After almost 12 months on site, we thought it would be a great opportunity to invite the entire Granit team to our site in Balham, South London. It is always very exciting to see our design vision being transformed into reality. Sitting on a quiet residential street and surrounded by old artisan style cottages, our client asked us to design a comfortable, modern family home whilst prioritising sustainability and energy efficiency.

What have we Designed?

As the project developed, we decided to aim for Passivhaus standard that led to the complete rebuild of the rear, whilst retaining the original, historic facade to the front. Our design utilises the existing external side passageway and transforms this into an entrance hall to help maximise the width of the Ground floor. The plan features a split-level that runs centrally down the core of the building as a way to provide a sense of separation between the intimate living space at the front, to the social Kitchen and Dining spaces at the rear. At First Floor, the bathroom sits within a metal cladded tower that marginally projects beyond the existing flank wall and runs to roof level to form a contemporary chimney. Two bedrooms are proposed at the rear, one of which includes a corner window that sits from table top level to the ceiling. Metal cladding is also proposed to the new mansard and dormer extensions at the rear where the master bedroom sits.

Our Sustainability Approach

We initially explored systems such as; SIPS (Structural Insulated Panels) and ICF (Insulated Concrete Form) but the complex existing site conditions meant this was very difficult to achieve. As a result, we finished up proposing a more traditional form of construction to the new build comprising an externally insulated wall system. Whilst in order to preserve the existing Victorian front facade, the internal walls were proposed to be insulated with natural wood fibre insulation. This enables the existing walls to breathe.
All external masonry walls were treated with a liquid applied airtight membrane internally and membrane sheets were fixed to the roofs to achieve a continuous airtight layer.
With the airtightness in place An MVHR system is proposed to act as the lungs to the building is also proposed to draw humid air out of the bathrooms, WC, Kitchen and Utility room and introduce fresh outdoor air into habitable rooms such as the living room, dining room and bedrooms.  The incoming air is filtered that enables the removal of pollen, diesel particulates and NOx to create a healthy indoor environment whilst removing the need to use gas or electricity for heating, something our client is very please with in the current climate! To ensure suitability all year round we have helped design this particular system to also provide a cooling function in summer.
Other design features include triple glazing, rainwater harvesting and solar photovoltaic panels.

 

The Result

This project aims to be an exemplar one that combines the beauty and character of a typical Victorian home in London with highest standards of energy efficiency.