How Much Does A Single-Storey Modular Extension Cost?

When planning a home extension in Milton Keynes, understanding costs is one of the most critical factors. A modular extension, rear single-storey ones are becoming increasingly popular thanks to their speed, quality, and cost-effectiveness. In this this article, we’ll break down the cost of modular extensions, explain the benefits of choosing this approach, and even provide a calculator to help you estimate your project.

Why Choose a Modular Rear Single-Storey Extension?

Modular extensions are a modern solution to home improvement projects. Built off-site and assembled on your property, they provide exceptional quality, reduced disruption, and faster timelines compared to traditional builds.

Key Benefits of Modular Extensions

1. Speed of Construction Modular extensions are pre-fabricated off-site in controlled factory conditions, meaning on-site assembly is quicker and less disruptive.
2. Cost-Effective Thanks to efficient manufacturing processes and reduced on-site labour, modular builds are often more affordable than traditional construction.
3. Sustainability Modular construction generates less waste, making it an eco-friendly choice.
4. Turn-Key Service With Vergolus, you get a comprehensive service covering designs, planning, construction, and finishing.
5. 25-Year Warranty Our modular extensions come with a 25-year warranty—longer than most traditional builders offer—providing you with long-term peace of mind.

Modular Extension Cost Breakdown

To give you a clear picture of the costs, let’s explore a real-world example and provide tools to help you estimate your project.

Example Project: 4m x 6m Living Room Extension in Milton Keynes

This example includes:

• Dimensions: 4m x 6m (24sqm)
• Features: 2m x 3m roof lantern on a Flat roof, 4m bifold doors, and underfloor heating
• Architectural Fees: ~£1,950 (for drawings, structural calculations, and planning applications)
• Construction Cost: ~£2,250 per sqm

Estimated Total Cost:

24 sqm x £2,250 = £54,000 Add architectural fees (~£1,950), and the total cost is approximately £55,950.

Modular Extension Cost Table

Below is an estimated cost table for various dimensions based on the going single storey house extension prices across the internet.

Dimensions (m)	3.0m	4.0m	5.0m	6.0m	7.0m	8.0m	9.0m	10.0m
3.0m	£31,050	£32,940	£40,950	£48,960	£56,970	£64,980	£72,990	£81,000
3.5m	£31,950	£37,980	£47,475	£56,970	£65,565	£75,060	£84,555	£94,050
4.0m	£32,940	£43,020	£54,000	£64,980	£75,960	£81,540	£97,920	£108,000
4.5m	£36,495	£48,960	£60,525	£72,990	£84,555	£96,300	£108,585	£119,250
5.0m	£40,950	£54,000	£67,950	£80,100	£94,050	£108,900	£128,250	£135,000

What’s Included and Excluded in the Prices Above

The prices listed in the table above are inclusive of the following:

• 20% VAT
• Foundations and structural steel frame
• External walls with brick slips, render, or cladding
• Flat roof construction
• Painted walls and ceilings
• Electrics and lighting
• Flooring
• Doors or windows (up to 3m wide)

What’s Not Included

The following are excluded from the prices but can be quoted for if required:

• Demolition
• Ground preparation
• Drainage
• Professional fees (e.g., architects, structural engineers)
• Authorities Fees (e.g., planning permission or building regulations)
• Creating new structural openings

Modular Extension Cost Calculator

Use our simple calculator to estimate the cost of your rear single-storey extension:

Vergolus Modular Extension Costs Calculator

Enter the total square metres of your extension to calculate the estimated cost: Enter Width (m): Enter Length (m): Calculate Cost

 

FAQs About Modular Extensions

1. How much does a single-storey modular extension cost?

On average, modular extensions cost £2,250–£2,750 per square metre, depending on design complexity and materials.

2. Are modular extensions faster than traditional builds?

Yes! Modular extensions are typically completed in as little as 2 weeks, much faster than traditional methods.

3. Do modular extensions require planning permission?

In most cases, rear single-storey extensions fall under permitted development rights. However, larger or unique designs may require planning permission. Vergolus handles this for you.

4. Are modular extensions durable?

Absolutely. Our modular extensions meet all UK building regulations and come with a 25-year warranty, ensuring they last for decades.

5. Can modular extensions be customised?

Yes. From layouts to materials and finishes, modular extensions are highly customisable to suit your preferences.

6. Are modular extensions eco-friendly?

Yes. Modular construction generates less waste and is more sustainable than traditional building methods.

7. What’s included in Vergolus’ turn-key service?

Our service includes everything from architectural drawings and planning applications to construction and final finishes.

8. Do modular extensions increase property value?

Yes. Well-designed modular extensions can significantly boost your property’s value.

9. Can I include features like roof windows and bifold doors?

Absolutely. Popular additions like roof windows, or lanterns and bifold doors are easily incorporated into modular designs.

10. How do I get started?

Simply contact Vergolus for a consultation. We’ll assess your needs, provide a quote, and guide you through the process.

Ready to Transform Your Home?

A modular rear single-storey extension is a smart, modern, and cost-effective way to add space and value to your property. At Vergolus, we provide a stress-free, turn-key solution tailored to your needs. Contact us today to get started on your dream project!