Can I just build an extension?

Author: Nathen Kuhic  |  Last update: Saturday, January 24, 2026

Any type of home addition or addition will require a building permit and architectural plans. Depending on the complexity of the work, a plan from a structural engineer could be sufficient. Before deciding on a type of extension, you need to know what's allowed in your area.

Is it possible to build your own extension?

Many will ask themselves 'can I build my own extension? ' and the answer is yes, of course. Undertaking a large proportion of the build on a DIY basis could enable you to reduce project costs by as much as a quarter.

What permission do I need to build an extension?

You need to apply for planning permission to extend or add to your house in the following circumstances:
  • Any part of the works are higher than the highest part of the roof of the existing house.
  • The height of the eaves of the extension would be higher than the eaves of the existing house.

Is it cheaper to build your own extension?

Yes it would be far cheaper to upgrade your existing extension as long as it is structurally sound. A professional competent builder would probably recommend various options, you could then choose which option would be the best for you your requirements and your budget.

Is it cheaper to add on or build up?

Adding onto your existing home is usually cheaper because it avoids buying new land and uses existing utilities, while building a new home involves higher costs for land, foundation, and separate infrastructure.

Savvy homeowner builds extension for less than £10,000 with help of YouTube tutorials

How much does it cost to add 1000 square feet to a house?

Adding 1000 square feet to your home can be a significant investment. The cost typically ranges from $125,000 to $250,000. This wide range is due to several factors: Materials and Finishes: Basic materials will keep costs lower, while high-end finishes can drive up the price.

Is it cheaper to build on or up?

In general, building up tends to be less costly than building out. When you factor in things like digging and pouring a new foundation, building out typically carries a higher price tag (though this isn't always true, and certainly depends on the size of the room and its purpose).

What is the cheapest way to extend a house?

Concrete blockwork and a concrete sub-floor tend to be the cheapest way to construct an extension. As well as the materials being cheaper, most trades are familiar with them so you won't need a specialist team to erect it.

What is the most expensive part of a house extension?

Typically, the most expensive part of a house extension is the foundation work and structural alterations required to support the new space.

What is the biggest extension without planning permission?

For rear extensions
  • Single storey rear extensions can be extended as far as 4m for detached houses and 3m for other houses. This can increase to 8m and 6m, respectively, with prior approval.
  • Double storey rear extensions can go as far as 3m from the original house as long as it's more than 7m away from the rear wall.

Can I draw my own plans for an extension?

Do I need an architect for my house extension plans and drawing? Although not a legal requirement, we highly recommend contacting an architect for your home extension.

How much is a single story extension?

They do not include VAT or professional fees. House extension costs: Single storey – A single storey extension in London will usually cost between £2,200 and £3,300 per sqm (£200 and £300 per square foot). £2,200 per sqm would represent cost-effective finishes and products.

Where do I start if I want to build an extension?

Planning permission

Council websites are a good starting point and you can also ask a building professional, such as an Architect, for advice. Permission can be granted subject to certain conditions or refused. Council planners consider issues such as impact on neighbours, character of the area and road safety.

Can you do your own extensions at home?

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U-Part wigs offer a quick and easy way to achieve a new look in under 30 minutes. These wigs are designed with a U-shaped opening and secure clips, making them simple to attach to your natural hair without the need for sewing or gluing.

Can you build an extension without foundations?

Yes, you can add a room to your house without a proper foundation, but it doesn't involve constructing a new room straight on the ground. You may add a second story or expand outward, any structural addition to a building requires a solid foundation for stability.

How much does a 10x10 bedroom addition cost?

The overall cost of a room addition is influenced by several factors including location, materials, labor, and permits. Typically, homeowners can expect to spend between $10,000 to $25,000 for a basic 10x10 room addition, but this can vary widely.

Can I build an addition on my house myself?

Yes, you can complete most of the planning and work by yourself, but unless you're a contractor or have lots of experience, it's best not to complete a full DIY home addition or demolition independently.

What is a bump out addition?

Bump-out additions (also known as micro additions) extend the size of an existing room in your home, often by just a few feet (although they can go up about 15 feet). Compared to other types of home additions, bump-outs are smaller in size, take less time to build, and are more affordable.

Can I build an extension for 50k?

A budget of £50,000 would comfortably provide the family plenty of options to choose from. Thus they get to choose whether they would want to opt for: A conversion of an existing loft, garage or even a basement, A single storey extension which is considerable larger or.

Is it cheaper to buy or extend?

Extending is almost always a cheaper option than moving home, unless you would be taking on a huge project such as digging out a floor below ground level, which is usually only done in London.

How to add a room to a house cheaply?

5 ways to add a room to a house cheap
  1. Build a bump-out addition. ...
  2. Finish a basement or attic. ...
  3. Create a FROG (finished room over garage) ...
  4. Add a sunroom. ...
  5. Consider a smaller addition.

How long does it take to build a 400 sq ft addition?

The estimate we give our clients is to expect 3-4 months or more for an addition of 1,000 square feet. A smaller addition of 200-400 sq. ft. will take 2-4 months. This is just an estimate, of course, and the exact time will depend on the factors listed above.

What is the cheapest type of house to build?

Prefab homes: Modular or manufactured homes are more affordable because their structures are partially built off-site, rather than building a fully custom house on-site. Tiny homes: A tiny home may be the cheapest type of house to build.

Is it cheaper to add on or move?

Although choosing to move or remodel is more than just a financial decision, the answer is clear -adding onto the existing house beats out moving from a dollars and cents perspective.

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