How Much Will A Double Storey Extension Cost To Build?

If you’re looking for ways to give yourself and your family more
floor space at home without having to move house, the ideal solution
could be the build a double storey extension. Not only can it enable
you to make your existing rooms larger, but a double storey extension
can allow you to add more new rooms, change your existing rooms’
layout and even increase your property’s value.

However, it’s
important to know how much this construction project could
potentially cost, so in this article, we’ll take a closer look at
the various costs involved in completing this type of project.

A Guide To
Sample Costs

Rather than
adding two separate single floor extensions, it can be a wise idea to
extend both storeys at the same time to save money overall while
reducing disruption and project time. However, there are many factors
to take into account when estimating the overall cost of completing
this kind of construction project.

The average cost
of a double storey extension comes in at between £1650 and £2150
per square metre, with additional costs including £500 – £1500 for
planning drawings, around £6000 for foundations, £36,000 for
framing, and about £14000 for framing. Then there are surveyors’
fees to add on of roughly £1250 as well as about £750 to budget for
a party wall agreement. On top of this amount, there will also be
additional expenses for internal fittings and fixtures.

Why Opt For A
Double Storey Extension?

If you’re
trying to decide whether a single storey or double storey extension
is best for your needs, it’s important to recognise the benefits of
completing both storeys at the same time. You’ll already be paying
for foundations and a roof for the new extension, and those costs
won’t increase if you extend both storeys rather than just one.

A double storey
extension also won’t take twice as long as a single storey one, and
the overall cost for a two-storey extension is only usually around
50-70% more than the cost of a single storey extension, so you’ll
save money in the long run if you’re considering completing
extensions on both floors separately.

Are There
Different Types Of Double Storey Extensions?

The location of
your double storey extension has a vital part to play in the benefits
that it will bring you and your family. If you make the wrong choice,
you could experience reduced privacy, reduced light, reduced access
to your garden, and obstructed views. There are four different types
of double storey extensions – side, front, rear, and wraparound
extensions, all of which come in at an average price of £66,000 to
£100,000, although if your chosen site is difficult to access, you
may need to pay more for your extension.

When choosing the
best type of double storey extension for you, bear in mind that a
rear extension will reduce the size of your garden dramatically, so
is best kept only for properties with large outdoor spaces. A front
extension also can prove problematic since it can completely change
the appearance of your property and it will also need to comply with
building regulations.

If you have a
semi-detached or detached properly, a side extension could be idea
since it will minimise the impact on your home’s appearance and
garden space, whereas a wraparound rear and side extension can give
you maximum additional space, although it will increase the length of
time your project will take to complete as well as the costs.

Budgeting For
A Double Storey Extension

Planning your
budget is essential when considering any construction project, and
there are some key elements you must factor into your calculations
when planning a double storey extension. They include:

  • Surveyor and
    architect fees
  • Materials
  • Finishes
  • Groundworks
  • Scaffolding
  • Insurance
  • Location
  • Drainage
  • Electrics
  • Room purpose
  • Doors and
    windows

  • Stairs
  • Outdoor
    openings

  • Planning
    permissions
  • Part wall
    agreement costs

  • Survey costs
  • The builder
    and contractors’ hourly rates

Will I Need To
Get Planning Permission?

All new
extensions have to meet structural and legal regulations. When it
comes to double storey extensions, several requirements come into
play with regard to granting of planning permission. For a start, you
cannot build a double storey extension if your home is located in a
conservation area, area of outstanding natural beauty, world heritage
site, or national park.

The planned
extension (along with any extensions that have already been added to
the property) mustn’t take up over 50% of the original house’s
total land area, and the ridge and eaves height of your extension
cannot be higher than the structure of the existing house. If the
extension is going to be located within 2m of the property
boundaries, the eaves cannot be over 3m in height, and a double
storey extension cannot be over 3m deeper than the existing house or
located within 7m of an opposing boundary.

Whenever
possible, the extension’s roof pitch and exterior materials should
match with the existing house, and no veranda or balcony is
permitted.

Is It Possible
To Build My Own Double Storey Extension?

It isn’t quick
or easy to build an extension to your home, especially when it comes
to double storey extensions that require working at height. Unless
you have excellent skills, you’ll struggle to complete the job to a
professional standard, and that could lead to some serious issues in
the long-run. It’s always best to seek help from a professional
when making any significant home improvements.