Case study / Weedon

A house at Weedon, extended by the practice that built it.

A bespoke contemporary house in a wooded plot in Northamptonshire, returned to its original architects by its new owner. The open car port beneath the cantilevered first floor became a light-filled project room, and a new detached car port took its place.

The house as we designed and delivered it, years before the extension. The recess beneath the cantilevered first floor, between the two stone piers, is the space this project turned into a room. Computer-enhanced image.

The facts

Home extension architects, Northamptonshire.

A householder application to West Northamptonshire Council, validated at the start of March 2022 and consented at the end of May, with no objections raised against it at any point.

The project

Twelve weeks, no objections.

12weeks to consent

Location: A private house near Weedon, Northamptonshire
Client: A private client, anonymised by agreement
Consent: West Northamptonshire Council, full householder planning permission granted 26 May 2022
Our scope: Architect and planning agent: concept through technical design, working drawings and the Building Control application
Status: Consented and delivered. Both the project room and the car port are built

On the council's public register: valid 1 March 2022, granted 26 May 2022, subject to two conditions. Full Building Regulations approval followed on 18 August 2022.

The brief

A new owner, and a house we knew.

The house is an uncompromising piece of contemporary architecture: timber cladding, a dry-stone plinth and generous feature glazing in a mature wooded plot. We designed it, and we saw it through to completion. Beneath its cantilevered first floor sat an open car port, useful and unloved.

Its new owner wanted that space to become a proper room. She came to us first for the original drawings, having worked out who had designed the building. We do not release drawings for someone else to build from, so we offered to do the work instead.

The new room: About 23 square metres, for two large desks, a feature window seat and a new entrance to the garden
The replacement: A new detached two-bay car port to the front, in untreated larch on a steel frame
The house: Bedrooms and utility at ground level, living lifted to the first floor to catch the light
The relationship: The practice that designed and delivered the original house, back on the same building

The route

No permitted development to fall back on.

The permission that allowed the house to be built in the first place had removed householder permitted development rights across the whole site. So there was no small-works route and no prior approval to lean on. A modest addition to a private house needed a full planning application, and needed to win it.

What that meant: Every element, including the detached car port, had to be applied for and justified
The validation query: Raised and resolved inside a working day, direct with the case officer
What delayed it: Council workload, settled by agreed extensions of time. The scheme itself was never in question
The decision: Granted with two conditions: a three-year commencement, and build in accordance with the drawings

The removal of permitted development rights is recorded on the face of the 2022 decision notice, which carries it forward from the original permission to build the house.

The scheme

The wall had one place it could go.

The balcony above the car port is not insulated. That single fact fixed the new wall's position: it had to line up exactly with the structure overhead, so the void could be filled and the room below could be warm. Everything else was designed around it.

The section

Where new meets old.

Read it at the junction. The new wall sits under the existing structure, the uninsulated void above it is packed with mineral wool, and the floor is set to match the level of the room next door so you walk straight through without a step.

The section. Zoom for the insulated void and the level threshold.

The front elevation

A room where the car port was.

The new wall sits back from the face of the building, so a shadow gap runs between old and new and the original lines stay crisp. It is rendered rather than clad, deliberately, so fresh timber never has to sit against fifteen years of weathered cladding.

The front elevation. The stone piers either side were kept.

The plan

Two desks, and a window seat.

The room had to earn every square metre. The window seat sits between two shelving units and frames the garden; the bi-fold doors open the whole end of the room; and the new entrance is positioned to work with the main door rather than compete with it.

Ground floor. The new work is the hatched wall; everything above it is the house as built.

The car port

Untreated larch, on a steel frame.

The replacement car port is a separate object, so it is free to be timber where the extension could not be. Untreated larch battens on a slim steel frame, under a shallow mono-pitch roof, left to silver down to the tone of the house.

The car port. Two bays, sized to replace exactly what the new room took.

The site

A tight envelope between the trees.

There was only one place the car port could stand: to the front, in the gap left between the existing trees, the overhang of the first floor and the access running down the side of the house. The trees around the wooded boundary were kept.

The site layout. Zoom for the car port and the retained trees.

The challenge

Add to it without leaving a mark.

The existing building set all the rules.

Adding to a confident piece of contemporary architecture is harder than starting from an empty plot. Anything new had to read as part of the original rather than as a bolt-on, and the house left almost no room to move.

Discuss your home

The recess beneath the cantilevered first floor at Weedon, between two dry-stone piers, under a band of slatted timber cladding. Computer-enhanced image.

The room could only sit inside the car port's existing frame, and the uninsulated balcony overhead fixed the wall's line to the millimetre. Outside, the new car port was hemmed in by the trees, the first-floor overhang and the side access. And with permitted development rights removed from the whole site, none of it could be built without a full permission.

The full story

Because we had designed the house, we did not have to relearn it. We knew what was behind every wall, which meant we could go straight at the real problem: the balcony above the car port has no insulation in it, so the new enclosing wall had to line up precisely with the structure overhead and the void above had to be packed out. There was no freedom to shift it for the sake of a better room, so the room was designed around the line the building gave us.

The rest was a discipline of disappearing. The new walls are set back so a shadow gap runs between old and new and the original's crisp lines survive. The finish is render rather than timber, chosen deliberately: new cladding against fifteen years of weathered boarding would have announced itself every time you looked at the house. The bi-fold doors are mirrored from the ones on the floor above, part of the terrace was kept rather than swallowed, and the window seat was positioned so the garden view drove the layout instead of the rear door killing it. The car port, being a separate object, was free to be timber, so it is untreated larch on a steel frame.

Then we ran the planning. A query on the submitted drawings was raised before validation and resolved inside a working day, direct with the case officer rather than back through the portal. After that the application simply sat in a queue: the council's workload pushed the decision back three times, and each time we agreed an extension of time and kept the officer engaged, while explaining to an understandably anxious client that the delay was the council's diary and not her scheme. It was granted on 26 May 2022 with no objections and two conditions. We lodged the Building Control application, which passed on 18 August, and issued the full set of working drawings the build was made from.

What we did

Consented and delivered.

Rickett Architects designed the original house and saw it through to completion. Years later we returned as architect and planning agent for the extension, took it from concept to consent and on to a built result. The builder and the structural engineer were the client's own.

The planning case

A clean application, patiently held.

Route: A full householder application, because permitted development rights had been removed from the site
Objections: None, at any stage
What we managed: A pre-validation query resolved in a working day, then three agreed extensions of time as council workload pushed the decision back
Outcome: Full planning permission, 26 May 2022, subject to two conditions

Twelve weeks from validation to consent, on an application that was never contentious.

The design

Held to the line the house gave us.

The constraint: An uninsulated balcony overhead, which fixed the new wall's position exactly
The junction: Stainless steel starter bars between new and existing structure, the void above filled with mineral wool
The finish: Render over blockwork, set back to throw a shadow gap, avoiding new timber against weathered cladding
The detail: Bi-folds mirrored from the floor above, a level threshold throughout, and part of the terrace retained

One window carries sound-insulating glass, because the railway is close.

The delivery

From concept to a built room.

Design stages: Concept design, then technical design and a full set of working drawings
Planning: We acted as the client's planning agent from submission to decision
Building Control: Full plans lodged by us and passed on 18 August 2022
Construction: Built by the client's own builder, working to our drawings, with their own structural engineer

A useful new room, and a car port that looks as though it was always there.