Guide to Converting a Conservatory into a Kitchen

11, Sep, 2026

Does your conservatory sit unused for much of the year because it is freezing in winter and too hot in summer? Many UK homeowners reach the same point and start looking at ways to turn this wasted space into a proper kitchen. But transforming a conservatory into an extension involves more than replacing the roof. 

You need to consider the structure, insulation, planning, Building Regulations, and the quality of the finished space. This guide covers the key decisions and what to look for before choosing a builder.

Should You Upgrade or Replace It?

If the structure is in good health, improving the roof, insulation, glazing, heating, and ventilation is a better idea. If you want an open-plan kitchen, better insulation and a stronger connection with the rest of the house, more substantial work might make more sense.

Think of the options as three routes:

• Upgrade the existing conservatory

• Adapt it into a more usable room

• Replace it with a full extension

The cheapest option is not always the best long-term choice. Your existing structure should decide how far the work needs to go.

What Does the Work Involve?

A successful project involves more than replacing the roof. First, the existing structure needs an assessment. The foundations, floor, walls, glazing and roof all affect what happens next. The kitchen layout comes next. Decide where the units, appliances, island, dining area and doors will sit before structural work begins.

Then address insulation, heating, plumbing and electrics. A kitchen produces heat, moisture and heavy daily use, so the room needs to perform like the rest of the house. Finally, the connection between the conservatory and the existing kitchen needs careful planning. A larger opening often creates a more natural open-plan layout, but it also introduces structural and Building Regulations requirements.

Can You Remove the Doors Between the Kitchen and Conservatory?

A conservatory under 30m² is normally exempt from Building Regulations when it meets specific conditions, including separation from the house by external-quality doors, walls or windows and an independent heating system. A new structural opening between the conservatory and the existing house requires Building Regulations approval.

So, removing the existing doors is not simply a matter of taking the frames out. The opening, support above it, insulation, and surrounding construction need proper consideration. 

Will Your Existing Foundations Be Strong Enough?

Your conservatory might look solid, but its original construction tells you more than its appearance. Some conservatories were built with lighter structures and foundations suited to their original design. A new insulated roof, heavier walls, or major structural changes might place different demands on the existing base. Before spending money on kitchen units and finishes, find out what the existing structure is suitable for.

How Much Will It Cost?

A current 2026 Checkatrade guide puts a full conservatory rebuild at roughly £15,000 to £25,000, while wider conversion guides reach higher figures where structural rebuilding, new foundations or a full kitchen are involved.

The main cost factors include:

• Structural work

• Foundations

• Roof replacement

• Wall and floor insulation

• New glazing and doors

• Plumbing and electrics

• Heating

• Kitchen units and appliances

• Flooring and finishes

Treat online prices as planning figures rather than a quote for your home. A site assessment gives a more useful starting point.

Do You Need Planning Permission or Building Regulations?

Planning permission and Building Regulations are separate checks. Conservatories follow the same planning rules as other house extensions. Permitted development rights apply only when the relevant limits and conditions are met. 

Previous extensions, planning conditions, Article 4 Directions, conservation areas and listed status might affect the position. Building Regulations become important when you create a structural opening, change the construction or integrate the conservatory with the main house. Check both before work starts.

A Real Denham Crescent Project in Colliers Wood

Denham Crescent has completed a project closely matching this type of work in Colliers Wood. The team opened up the area with new steelwork to create an open-plan kitchen, installed new concrete floors and screeding, fitted a new kitchen with a quartz worktop and installed a new conservatory roof with French doors.

The work also included new electrics and plumbing, underfloor heating, plastering, skimming, painting and decorating. The project received approval from the local Building Control Officer. A successful project involves more than changing the roof. Structure, services, heating, kitchen installation, and finishing all need to work together.

Is It Better to Adapt the Conservatory or Build a New Extension?

The right choice depends on the existing structure.

Adapt the conservatory when:

• The foundations are suitable

• The existing footprint works

• The frame and walls are in reasonable condition

• You want to retain part of the existing structure

Consider a new extension when:

• The foundations are unsuitable

• The structure has significant defects

• The existing footprint does not suit your kitchen

• You want major changes to the layout

Get both options assessed before committing. A cheaper project loses its value if major rebuilding becomes necessary halfway through the work.

If you want to transform a conservatory to an extension, Denham Crescent offers structural work and services through to kitchen installation and finishing. Contact us today.