Bungalow Loft & Rear Extension

Eltham, South East London

2021–2022

01 / 04

Project overview

This detached bungalow had an existing room-in-roof conversion, but the space was cramped, poorly insulated and affected by leaks. The clients wanted to create two much larger double bedrooms with en-suites for their growing family, while also upgrading the thermal performance of the roof.

At ground-floor level, the project included a new single-storey rear extension to create a large open-plan kitchen, dining and living space, giving the family much needed additional living accommodation.

Structural solution

Following an initial inspection, ANDO Engineering recommended removing the existing roof and ceiling structure entirely and rebuilding from new. Although this was a more substantial intervention than initially envisaged, it allowed the constraints of the old conversion to be removed altogether.

A new steel frame was designed to form the primary structure of the replacement roof, with timber construction spanning between the steel members. This created fully vaulted ceilings to the new bedrooms and allowed the full volume of the roof space to be used, producing significantly larger and more open rooms.

At the rear of the bungalow, a full-width opening of approximately 8.5 m was formed between the existing house and the new extension. A steel moment frame was designed to provide the required support and stability while making use of the existing foundations, avoiding the need for substantial new pad foundations or underpinning.

The main beam was also designed to be pre-loaded during construction, limiting dead-load deflection and allowing a more efficient steel section to be used.

Services provided

Replacement vaulted steel roof structure
New loft floor structure
Timber roof framing
Stair and floor openings
Rear extension structure
8.5 m-wide opening to the existing bungalow utilizing a steel moment frame
Foundation design and assessment
Construction-stage structural support