Start trial
  • Extensions
  • Loft conversions
  • Kitchens & bathrooms

Plan your extension. No building knowledge needed.

Answer plain questions and Prillo writes the specification builders price from. Then compare their quotes and run the job, step by step.

Write my specification See an example project

7 days free, then £8.99 a month. Cancel anytime.

Try it Three taps. Watch your specification write itself.

Question 1 of 3How wide is the back of your house?

Nothing is saved until you make an account.

SpecificationRear extension
  1. Answer a question and watch this fill in.
  • Roof
  • Rooflights
  • Doors & windows
  • Drainage
  • Electrics
  • Heating
  • Finishes

Not sure what to ask builders for?

Most homeowners have never written a specification. So every builder guesses, the quotes don’t compare, and the gaps cost you later. Prillo asks the right questions and writes it for you.

From first idea to final payment

Every step, explained as you go

1 · Specify
Hands marking up a floor plan beside a tablet in a half-stripped kitchen

Bathroom

  • Tiles 3
  • Sanitaryware 6
  • Basin taps
  • Basin waste
  • Heating 1

No idea how to write a specification? You don’t need one.

Answer plain questions. Prillo writes the specification builders price from, down to the basin waste.

  • Not sure? Prillo assumes and flags it
  • Edit or delete any line
  • Send trades only their part
2 · Quote
A builder measuring the back wall of the house during a site visit

Your quotes

Hartley Build £48,200

Oakline Homes £51,750

Brick & Beam £44,900

Excludes flooring

Is this quote fair? See for yourself.

Every quote checked against your specification. Missing items and extras flagged before you sign.

  • Exclusions flagged up front
  • Odd terms shown separately
  • Invite another builder in two taps
3 · Permissions
Two neighbours chatting over a garden fence behind their terraced houses

Needed for your project

Party wall notice

Serve it at least a month before digging starts.

Party wall? Know in week one, not week nine.

Prillo tells you which permissions your project needs, and when.

  • Matched to your home
  • Plain words, official sources
  • Every certificate in one place
4 · Costs
A couple reviewing their project budget together on a phone

Your budget

£55,000

£39,600 committed · £5,000 contingency

Know what it’ll really cost

Builder, kitchen, engineer, fees: every cost in one total.

  • Builders never see your budget
  • Every cost counted once
  • Paid, due and still to choose
5 · Choices
Tile samples, a door handle and a paint card on a window sill in the plastered extension

To choose

Floor tiles Before second fix

Door handles Finishing

Rooflights Chosen

Tiles chosen before the tiler asks

What to decide, room by room, in the order your builder needs it.

  • A board for every room
  • Who buys what, clear
  • Choices flow into the spec
6 · Build
A new steel beam in place over the opening into the extension

Rear extension

  1. Wk 1Groundworks
  2. Wk 2Drainage
  3. Wk 3Walls
  4. Wk 4Steel beam
  5. Wk 5Roof
  6. Wk 6Doors

Week 4: steel in. Four new photos.

See progress without chasing. Pay only for stages that are done.

  • “How’s it going?” answered
  • Pay for stages, not dates
  • Every change on record

Three quotes. Spot what’s missing.

Cheapest quote? Not always the cheapest job. Try it Tap “What’s not in this quote?”

Brick & Beam£44,900

Excludes flooringCheapest

Hartley Build£48,200

Matches your specificationEverything priced

Oakline Homes£51,750

Adds extras£3,550 more than Hartley

Write my specification

From idea to quotes

  1. Today

    Answer the questions

    A few plain questions. Prillo writes the specification.

  2. Tonight

    Send it to your builders

    By email. No account needed to price it.

  3. This week

    Compare what comes back

    Lined up side by side, gaps flagged.

30 years in construction taught me: most disputes start with a vague quote. Handshake agreements rarely work. Prillo gives you a clear, written scope both parties agree on.

Prillo’s founder · Chartered surveyor

£8.99 a month, less than a tin of paint

7 days free. Nothing worth sending by day 7? Walk away.

Prillo Home

£8.99 a month

Billed monthly

Everything, for every project in your household.

  • Your specification, written from plain questions
  • Quotes from any builders you invite, compared like for like
  • Permissions, costs, choices and the build, in one place
  • Builders never see your budget
Write my specification

Builders never see your budget

They only see what you send. Nothing is ever sold.

What people ask before they start

I’ve never done a building project. Is Prillo for me?

Yes. That’s exactly who it’s for. Prillo explains each step as you reach it.

Do I need drawings to start?

No. Answer a few questions and Prillo writes the specification. Add drawings any time.

Can I use a builder I already know?

Yes. Invite any builder by email.

Will my builder actually use it?

They don’t have to sign up. They price from a link.

What if a builder’s quote isn’t on your terms?

Prillo shows it separately and lists what’s missing.

Can builders see my budget?

Never. They only see what you send them.

Does Prillo replace an architect or surveyor?

No. Prillo tells you when you need one, like a structural engineer or party wall surveyor.

What does it cost?

7 days free, then £8.99 a month for every project in your home. Cancel anytime.

The finished rear extension at dusk, glazed doors open to the garden

Know exactly what to ask for

Start tonight with a few plain questions.

Write my specification

7 days free, then £8.99 a month. Cancel anytime.