What size extension can
I build without planning
permission?
Donna, via email
Under Permitted Development (PD) rules you
can extend the full width of the rear elevation
to a depth of 3m for an attached property and
4m for a detached property. There are other
limits and conditions that can be found on http://www.
planningportal.co.uk.Do I need an architect to
plan an extension?
Tom, via Twitter
It’s highly advisable to get drawings carried out
to satisfy both the planning department and
building control. This gives you the peace of
mind that if your builders follow these plans,
the extension is being built to the right size
and in the right way to comply. It will also be
easier to sell the property with the plans in
place. However, in theory you do not require
drawings by an architect and if your builders
are extremely competent, it could be built
in accordance with regulations without any
drawings or specification. Some companies will
offer a Design & Build service which will mean
you do not have to engage a separate architect
and this could be an avenue worth pursuing to
have everything under one roof.READER CLINIC
Answering all of your questions on self-builds, conversions, extensions, and everything
in-between! Get in touch with your queries by emailing us at [email protected]Reader Clinic Ask an Expert
How much does it cost
to build an extension?
Rebecca, via email
This will vary around the UK, but in London
expect to pay between £1200-£1800 per sqm.
There are a multitude of factors that will
add additional costs like finishes, roof style
and glazing.How long does it take
to build an extension?
Derek, via email
An average rear single storey extension of 5x4m
should take around 8 weeks from foundations
to decorating. A double storey would be
between 12-16 weeks depending on scale and
specification. Bear in mind that weather related
issues could increase the timings; brickwork
cannot be laid in freezing temperatures, and if it
were a particularly wet and cold season, drying
out times would be longer. There could also be
unforeseen problems like underground drainage
requiring alteration that would delay time on
site. However, surveys can be undertaken at
additional cost to limit these types of issues.Can I extend on an
existing extension?
Chris, via email
Yes, but the limits would still apply under
Permitted Development (PD). So if you have
already extended you may only have a small
amount of PD allowance remaining.
You can apply for Planning Permission to
extend further.How much value can
an extension add to
my house?
Holly, via email
A well thought out extension will always add
value and this can be as much as 20% increase
on the property value, but price caps on the area
will apply. You can check the sqft value of your
home on websites like Zoopla which will give
you a guide to calculate the increase in value of
your extension.020 8819 3883
http://www.jefferyandwilkes.co.uk
@jefferywilkesukI
n this issue we focus on
extensions with expert
advice from Greg Wilkes, the
managing director at Jeffery
& Wilkes, a design and build
company that specialise in loft
conversions, home extensions,
and home refurbishments.