House Extensions in Chorley: Planning, Costs & Timelines

Thinking about adding space without the hassle of moving? A well-planned extension can unlock a bigger kitchen, a brighter family room or a practical utility space, all while lifting the value of your home. If you are comparing companies for house extensions in Chorley, this guide covers the key steps: planning permission, design choices, realistic costs, and how to keep timelines on track.

Start with the “why” and the layout

Before drawings or budgets, get clear on the problem you are trying to solve. Do you need an open-plan kitchen-diner, a ground-floor bedroom with ensuite, a home office, or better storage and circulation? The right answer shapes the type of extension:

1. Single-storey rear for larger kitchens, dining and living space.
2. Side return for period terraces, great for bringing light into narrow plans.
3. Wraparound for maximum footprint on corner plots.
4. Two-storey to add bedrooms and bathrooms as well as downstairs space.
5. Dormer loft when the plot is tight but roof volume can be used.

Sketch a simple wish list and rough layout. A one-page brief helps everyone quote like-for-like and avoids costly changes later.

Planning permission in Chorley: what to know

Plenty of extensions can be built under permitted development if your home and proposal meet certain rules on size, height and materials. That said, there are limits around boundaries, roof heights and previous additions. You will still need building regulations approval to confirm structure, insulation, fire safety and electrics.

A good workflow is:

1. Feasibility chat to confirm what is likely under permitted development versus full planning.
2. Measured survey and concept drawings to test layouts, glazing and roof options.
3. Planning or lawful development application if needed.
4. Building regs drawings with structural calculations for steels, foundations and roof build-ups.

If you want a local team that handles this every week, browse Ashbarn’s Residential projects to see typical detailing and finishes.

Tip: Even when permitted development applies, notifying neighbours and agreeing site access early keeps the build smooth.

What does a Chorley extension cost?

Costs vary with size, spec and access. As a sensible guide for the North West:

1. Single-storey kitchen/diner: from ~£1,800–£2,400 per m² for a straightforward spec; £2,500–£3,200+ per m² for higher-end glazing, UFH and a quality kitchen fit.
2. Two-storey: usually adds 40-60% more than a comparable single-storey shell because upstairs needs extra structure, stairs and bathrooms.
3. Loft dormer: often sits in the £45,000-£75,000 bracket depending on scale, roof work and ensuite.
4. Professional fees: planning/building regs drawings, structural design and approvals are commonly 8-12% of build cost across the lifecycle.
5. Contingency: ring-fence 8-12% for surprises and small scope changes.

These ranges assume sensible access, typical ground conditions and a mid-range finish. Tight sites, tricky ground or bespoke glazing will push costs up. The right builder will price a clear inclusions list so you are not caught by extras later.

Timelines you can trust

A realistic timeline for house extensions in Chorley usually looks like this:

1. Design and approvals: 6-12 weeks depending on complexity and whether full planning is required.
2. Pre-start (lead times, ordering windows and steels): 2–4 weeks.
3. On-site build:
4. Single-storey: 10-16 weeks
5. Wraparound or two-storey: 14-24 weeks
6. Loft dormer with ensuite: 6-10 weeks
7. Snagging and handover: 1-2 weeks

Weather, bespoke items and late decisions are the common reasons projects slip. A weekly site update and early product selections go a long way to keeping dates intact.

Design details that pay you back

A little extra thought in design can make a big difference to how the space feels and performs:

1. Daylight: combine a modest rooflight over worktops with larger panes facing the garden. Balance views with solar gain.
2. Zoning: use a pocket door or a change in floor finish to separate cosy TV time from the cooking zone.
3. Storage: steal 300–500 mm along a wall for tall cupboards and utilities. Hidden storage beats clutter every time.
4. Heating and comfort: underfloor heating suits open-plan spaces; pair with good insulation and trickle ventilation so winter is warm and summer doesn’t overheat.
5. Electrics: plan sockets, task lighting and smart controls on the drawings, not on the fly.

How to choose the right builder

When you gather quotes, look for a team that works locally and can show similar projects within 10–15 miles. Ask for:

1. A line-by-line breakdown of labour and materials.
2. Inclusions and exclusions in plain English.
3. Provisional sums for items you will pick later, like sanitaryware and flooring.
4. A payment schedule tied to milestones you can see, not dates.
5. A programme showing key phases from foundations to finish.
6. References from recent clients and ideally a live site you can visit.

The best partners for house extensions in Chorley are not usually the cheapest on paper. They are the ones who communicate clearly, keep a tidy site and hand over work that looks good years later.

What Ashbarn brings to Chorley projects

Ashbarn Construction delivers residential extensions across Chorley and the surrounding Lancashire towns. Homeowners choose them for:

1. Joinery-led finishing with sharp lines, well-fitted doors and clean reveals.
2. Transparent pricing with proper inclusions and sensible allowances.
3. Realistic timelines and a single point of contact throughout the build.
4. Respect for your home with protection, tidy housekeeping and clear neighbour communication.

See what that looks like on real homes in the Residential gallery, then use it as a benchmark when you compare quotes.

A simple step-by-step plan

1. Site visit: talk through space needs, budget and constraints.
2. Concept and budget check: agree the footprint, roof type and glazing approach.
3. Detailed drawings: planning or lawful development route, then building regs with structure.
4. Three like-for-like quotes: same drawings and spec to keep it fair.
5. Pre-start meeting: site rules, neighbour notices, deliveries, protection of finishes.
6. Weekly updates: progress, decisions due, and any variations priced before work proceeds.
7. Snagging and handover: written list, clear dates and manuals for your new kit.

FAQs: House Extensions Chorley

Do I always need planning permission?

Not always. Many single-storey rear extensions fit permitted development. You still need building regs approval. Your designer and builder can confirm the right route for your property type and previous alterations.

Will an extension add value?

In most cases, yes, especially when it improves kitchen/dining space or adds a bedroom and bathroom. Value depends on finish quality, layout and local comparables.

How do I avoid budget creep?

Freeze the layout early, select big-ticket items before ordering (windows, kitchen, flooring) and approve any changes in writing with costs and time impact.

Can I live at home during the build?

For single-storey projects, many families do. Expect dust and disruption during structural works. A phased plan and temporary kitchen setup help a lot.

Ready to expand your Chorley home?

If you want straight answers on feasibility, cost and timeline, start with a quick chat with Ashbarn. Share your brief, look at similar local work and get a clear path to planning and building with confidence.