Kitchen Extension Ideas That Transform Your Home (With 2025 Costs)

The kitchen-diner extension is the UK's most sought-after home improvement. Open the back of your home, flood the space with light, and create a room where your family genuinely wants to spend time together. If you're planning a kitchen extension in Hampshire or Surrey, here's everything you need to know — from design inspiration to real costs.

The Most Popular Kitchen Extension Types

1. Rear Extension with Bifold or Sliding Doors

The classic. A single-storey extension to the rear of the house, opening onto the garden with large bifold or sliding doors. When the doors are open, the inside and outside become one seamless space. Cost: £35,000–£60,000 including a new kitchen.

2. Side Return Extension

Perfect for terraced and semi-detached homes with a narrow side passage. Filling in the side return widens the existing kitchen, often by 2.5–3.5 metres. This is one of the most transformative extensions relative to its cost. Cost: £30,000–£55,000.

3. Wrap-Around Extension

Combines a rear and side return extension to create a dramatically larger L-shaped ground floor footprint. The ultimate kitchen transformation — and typically the most expensive. Cost: £55,000–£100,000.

4. Orangery Extension

A more architecturally refined option featuring brick pillars, large glazed sections, and a lantern roof. Creates a beautiful, light-filled dining and living space. Cost: £40,000–£75,000.

Design Ideas to Inspire Your Kitchen Extension

• Roof lanterns: Nothing floods a kitchen extension with more natural light than a frameless roof lantern over the dining table area.
• Full-width island: A large central island becomes the heart of the open-plan space — for cooking, dining, and socialising.
• Skylights in the existing kitchen: Where the extension meets the original house, a strip skylight ensures no dark zones.
• Underfloor heating: Far more practical than radiators in an open-plan space, and allows large glazed areas without cold draughts.
• Utility room in the extension: Adding a utility room within the extension footprint keeps the kitchen itself clear and clutter-free.
• Flush threshold: A level transition from internal flooring to the garden patio makes the spaces feel truly connected.

Kitchen Extension Costs (2025)

Project Element	Budget	Mid-Range	Premium
Extension Shell (5×4m)	£28,000	£38,000	£52,000
Kitchen Supply & Fit	£8,000	£18,000	£40,000+
Bifold/Sliding Doors	£4,500	£7,000	£12,000
Roof Lantern	£2,500	£4,500	£8,000
Underfloor Heating	£1,500	£2,500	£4,000
Total	~£45,000	~£70,000	£116,000+

Top Tips for a Successful Kitchen Extension

1. Think about solar orientation — a south or west-facing extension will be naturally warmer and brighter.
2. Invest in the glazing — premium bifold or sliding doors make a dramatic visual difference and are better insulated.
3. Plan your electrics before plastering — add more sockets than you think you need.
4. Consider acoustic underlay beneath hard flooring in open-plan spaces.
5. Budget for landscaping and patio — the connection to the garden is half the point.