Whole-House Expansion & First-Floor Addition

Summary:

A referral from the project architect, this commission involved converting an irregular-shaped bungalow by extending on all sides to create a substantially larger footprint, then removing the existing roof and constructing a new upper storey to add three bedrooms and a bathroom. Alongside the new accommodation, the brief called for comprehensive upgrades to structure, services and thermal performance, with an emphasis on long-term sustainability (air source heat pump and solar PV).

Working from the architect’s drawings, we coordinated structural design for the new storey and the multiple side/rear additions, sequencing steelwork, load paths and temporary works. We planned phasing to keep the shell weather-tight between roof removal and new construction, aligned M&E specifications with low-carbon heating and solar generation, and agreed a clear programme covering enabling works, superstructure, first fix, envelope, second fix and finishes. Early decisions on insulation build-ups, airtightness details and services routes reduced rework risk and ensured tidy interfaces at handover.

Scope of works

Structural alterations & extensions

We executed multiple perimeter extensions to regularise the plan and increase ground-floor space, then removed the original roof to form a full new upper level. Structural steel and engineered timber solutions supported new spans, openings and floor loads, with localised alterations to the existing shell to accommodate revised circulation and room layouts.

• Multi-side footprint enlargement to the ground floor
• Removal of existing roof; new first-floor structure formed
• RSJs and engineered members installed; temporary works management
• New openings and lintels to suit reconfigured internal layout

Building envelope & thermal upgrades

The upgraded envelope combined internal and external insulation strategies to improve U-values, limit cold bridges and support efficient heating. We completed silicone render externally for a durable, low-maintenance finish, and fully replastered internally to a high-quality substrate for decoration.

• Internal and external insulation to specification
• New airtightness details at junctions and penetrations
• Silicone render to façades; full internal plaster finish

Mechanical, electrical & renewable systems

The property was fully rewired and replumbed, with new distribution, zoning and controls to suit the enlarged plan. Systems were designed to work cohesively with an air source heat pump and solar panels, improving efficiency and running costs.

• Complete electrical rewire, boards, circuits and certification
• New plumbing throughout, hot/cold distribution and drainage tie-ins
• Air source heat pump integration; solar PV provision and coordination
• First and second fix to all new/altered spaces

Kitchens, utilities & bathrooms

We installed a new kitchen and utility, plus two bathrooms, one en-suite and a ground-floor WC. Works covered substrates, first/second fix services, fitted furniture, sanitaryware, tiling and finishes, delivering a consistent standard across the home.

• Kitchen and utility installation to agreed layout/spec
• Two family bathrooms, one en-suite, and a WC fitted and finished
• Tiling, flooring, joinery and decoration to completion

Outcome

The project transformed a constrained bungalow into a well-planned two-storey family home with a coherent ground-floor layout, three additional first-floor bedrooms and a new bathroom. Thermal upgrades, together with the air source heat pump and solar PV, significantly improved energy performance and future-proofed the property’s running costs. Internally, the new kitchen, utility and bathrooms were completed to a clean, modern finish, with services, structure and envelope working in concert behind the scenes to support comfortable, efficient living – all delivered within an eight-month build.