How Much Does a Granny Annexe Cost in the UK?

As multigenerational living becomes more common in the UK, the granny annexe is rising in popularity as a flexible, private, and practical solution.

But how much does it really cost to build one—and what are the options, from bespoke brick builds to prefabricated garden pods?

In this guide, we’ll break down the average cost of a granny annexe in the UK, explore what influences the price, and compare a range of options—including how prefabricated solutions like Hully Pods offer a stylish and cost-effective alternative.

What Is a Granny Annexe?

A granny annexe is a self-contained living space built within the grounds of a main property—usually designed for elderly family members, adult children, or as guest accommodation.

It typically includes a bedroom, bathroom, living area, and sometimes a kitchenette.

Annexes can be attached to the main house, converted from existing structures, or built as freestanding garden buildings.

How Much Does a Granny Annexe Cost in the UK (2025)?

The cost varies based on the build type, size, and internal spec. Here’s a breakdown of the typical price ranges:

Prefabricated granny annexes offer one of the best value-for-money options, especially where space, time, and budget are limited.

What Affects the Cost of a Granny Annexe?

Several factors will influence your final cost:

1. Size & Layout

Naturally, larger spaces cost more to build. A compact pod with one room is far more affordable than a multi-room extension.

2. Self-Contained Features

Adding a bathroom or kitchen adds to both materials and utility connection costs. Plumbing and drainage are key price drivers.

3. Interior Finish & Insulation

From basic cladding to underfloor heating and energy-efficient glass, your interior choices can add £5,000–£20,000 depending on spec.

4. Planning & Regulations

Depending on use and structure, you might need planning permission. Hiring a planning consultant could cost between £500–£2,000.

5. Site Prep & Groundworks

Foundations, access, drainage, and utility routing can add significant costs—typically £3,000–£10,000 depending on the site.

Real-World Example: Hully Pods as a Cost-Effective Annexe Solution

Hully Pods offers a range of prefabricated, stylish garden pods that work as compact granny annexes—perfect for short- or long-term accommodation without the time or budget of a traditional extension.

Example: Skipjack Pod – From £4,495

• Internal dimensions: 2.3m x 2.2m x 2.6m
• Ideal for single-room accommodation or as a guest suite.
• Add optional electrics, solar panels, or interior upgrades.
• View Skipjack Pods →

Example: Schooner Pod – From £6,895

• Internal dimensions: 2.3m x 2.2m x 3.8m
• Offers enough room for lounge/sleep combo or office/living split.
• Also available in a glass-fronted version for a modern garden look.
• View Schooner Pods →

These pods offer many of the same comforts as a traditional annexe—insulation, heating, electrics—at a fraction of the cost and with less planning complexity.

Hidden Costs to Be Aware Of

Even with a prefab build, it’s wise to budget for:

How Granny Annexes Compare to Other Space-Saving Options

Conclusion: What’s the Best Value for Your Needs?

If you’re looking for a fast, flexible, and budget-friendly way to add liveable space to your home, prefabricated options like Hully Pods offer excellent value.

With models starting from under £5,000, they’re ideal for:

• Elderly relatives needing privacy and proximity
• Adult children returning home
• Guest spaces or part-time rentals
• Home studios or remote workspaces

Before committing to a major extension or full build, it’s worth comparing pod options. Visit our Pod Price & Size Comparison Page to explore what’s possible for your garden—and your budget.

Next Steps

Got a question about pod delivery, planning, or installation?
Speak to the Hully Pods team—we’ll help you explore what’s possible based on your garden layout and needs.