If you’re considering a house extension in Hull, one of the first questions you’re likely to ask is: how much is it going to cost? Whether you need more living space, a larger kitchen, or an extra bedroom, a well-planned extension can significantly improve your home’s layout, functionality and value.
However, extension costs can vary greatly depending on the type of extension, the size, the complexity of the work, and your choice of finishes. In this blog, we break down the typical costs of a house extension in Hull, along with key factors that affect pricing, so you can start planning with confidence.
Average Cost of a House Extension in Hull
As a general guide, you can expect the following ballpark figures for house extension costs in Hull:
- Basic single-storey rear extension: £1,500 to £2,200 per square metre
- Higher-spec single-storey extension: £2,200 to £2,800 per square metre
- Two-storey extension: Add approximately 50–60% more to the cost of a single-storey build
- Loft conversion with dormer: £30,000 to £50,000
- Garage conversion: £12,000 to £25,000 depending on size and internal finish
For example, a 4m x 5m single-storey extension in Hull could cost anywhere from £30,000 to £50,000, depending on how complex or high-spec the build is.
Factors That Affect Extension Costs
Type and Size of Extension
A small utility or WC extension will cost far less than a large kitchen-diner with bi-fold doors and skylights. Side returns, wraparound extensions, and double-height builds also require more materials and more structural input.
Ground Conditions
Foundations can be a hidden cost. Poor ground conditions, clay soil, or proximity to drains can require deeper or reinforced foundations, which adds cost and time to the build.
Design and Layout
Open-plan spaces with structural steelwork, large glazed openings, or bespoke features will naturally cost more than simpler layouts. Roof design (flat, mono-pitched, hip or gable) also influences price.
Planning and Regulations
Some extensions fall under permitted development rights, but many in Hull—especially in conservation areas like The Avenues—will need full planning permission. You’ll also need detailed building regulations drawings before work starts.
Finish and Specification
The final cost of your extension depends significantly on your internal finishes. Kitchen and bathroom fittings, underfloor heating, lighting, flooring, and joinery choices can easily account for a third of the final spend.
Cost of Professional Services
Don’t forget to factor in the cost of architectural and professional services, which may include:
- Architectural drawings and planning applications: From £800 to £2,000 depending on complexity
- Building regulations drawings: Typically £750 to £1,500
- Structural engineer calculations: £300 to £1,000
- Planning fees (Hull City Council): £258 for a householder planning application
- Building control fees: Usually £500 to £900, depending on the size of the project
At CK Architectural Hull, we provide fixed-fee packages for design, planning, and building regulations drawings, helping you stay in control of your budget right from the start.
Is a House Extension Worth the Investment?
In many cases, yes. A well-designed extension can increase your property’s value, especially if you’re adding an extra bedroom, bathroom, or expanding the main living area. In Hull’s competitive housing market, space and flexibility are strong selling points.
The return on investment depends on your location, the type of extension, and the overall finish. Properties in areas like Kingswood, Anlaby, and Willerby that have been extended to a high standard often see a strong uplift in market value.
Keeping Costs Under Control
Here are some tips for managing your extension budget in Hull:
- Work with an experienced architectural designer who understands local planning rules
- Get detailed building regulations drawings to avoid surprises on-site
- Choose builders with proven experience and check their references
- Be realistic with finishes and look for quality mid-range products
- Always set aside a contingency budget of at least 10 to 15 percent
Start Your House Extension Project in Hull
If you’re ready to explore your options for extending your home in Hull, get in touch with CK Architectural today. We offer free consultations, honest advice, and full support throughout the process. From concept design to planning approval and detailed drawings, we’ll help you bring your extension to life with clarity and confidence.
Contact us now to get started.
