What you get
01

A document that says which numbers are real.

Most cost documents present their figures as though they were equally true. A quoted window price and a rule of thumb sit in the same column with the same authority. Ours does not.

Length20 to 40pages, depending on the project
Consultation1 hourgoing through it line by line with you
Every line is one of three things, and it says which.Seven lines below, from a 45 m² rear extension in Edinburgh. Three priced, two allowed, two still open.
PricedA real figure from a named supplier, carrying the date they gave it and the period they said it stands for.
AllowedNot yet priced by a supplier. Set from benchmark data, declared as an allowance, never buried in a rate.
OpenSomething that could still move, shown as a range, with what it would take to settle it.
An arko cost plan · extract 69% priced
Windows and doors
Window manufacturer · 2 Oct · held 9 months
£28,400
Timber frame
Timber frame supplier · 3 Oct · held 12 months
£34,200
Cladding
Cladding mill · 6 Oct · no increase in 4 years
£11,900
Roofing
Allowance · benchmark £180 / m²
£9,600
Insulation
Allowance · benchmark £32 / m²
£4,100
Foundations
Open · subject to soil investigation
£12k to £18k
Steel to opening
Open · subject to engineer’s calculations
£3.2k to £6.4k
Total, as a range
£103,400 to £112,600
Priced coverage69%
£74,500 of the £108,000 carries a real price from a named firm, with the date it was given and how long it stands.

Illustrative extract. The method is real and so are the hold periods. The figures are a worked example and the suppliers are described rather than named. The coverage figure opens every plan, and we have not seen anyone else in this market publish one.

The rule we never break
02

Two totals, not one.

Most cost advice quotes the building works and stops. That figure is real, and it is not what leaves your account. On the worked example, the building was priced correctly and the budget still broke by sixty seven thousand pounds.

Building works
£147,200

What a builder would quote. Accurate, and the number most people are given.

What you actually pay
£214,753

Adding VAT, a calculated contingency, and the professional and statutory fees nobody mentions at concept stage.

The gap£67,553or 46% on top of the quoted figure
Every arko plan carries both, side by side, with the gap itemised. It is the single most useful page in the document, and the one that should have existed before you spent anything.

Both totals, on your own project.

From £1,800. Two weeks. Four questions to start.

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Two versions
03

One leaves the structure open. The other prices it.

The open items on most projects are the same two. What the foundations have to do, and what has to hold up the wall you are taking out. Both can only be ranged until an engineer has looked. Pro appoints one, included, and turns both into prices.

Cost plan

Standard

From £1,800
69%Priced coverage
  • The envelope priced by named suppliers, dated, with the hold period each one stated
  • Allowances for roofing, insulation and the rest, every one of them traceable
  • Foundations and structure left open, ranged, with what it would take to settle them
  • A calculated contingency, derived from your project rather than rounded to 10%
  • The risks that could move it, each costed, with how to resolve them
  • Savings options with amounts against them, costed rather than editorialised
  • Both totals, building works and what actually leaves your account
Cost plan Pro

With structural

From £3,900
87%Priced coverage
  • Everything in the standard plan
  • A chartered structural engineer, appointed and paid by us
  • A site visit, so the existing building is looked at rather than assumed
  • Calculations for beams, lintels and new openings
  • Foundation design to the proposed layout
  • Those elements priced rather than ranged, and the calculations are yours to take to building warrant
What we stand behind

Outside the range, the fee comes back.

Every plan states a range rather than a single number. If the building works come in outside that range, and the design has not changed since we priced it, we refund the fee in full.

We would rather carry that risk than publish a figure we are not willing to stand behind. It is also the reason the open items are declared as open instead of being quietly averaged into the total.

What Pro does not cover

A full ground investigation where the engineer calls for one. Boreholes, contaminated land, made ground or former mine workings are passed on at cost, with the figure agreed before anyone instructs anything. On most extensions, trial pits and a site visit are enough, and that is what the fee assumes.

The percentages above come from the worked example on this page. Your project will differ, and we tell you the realistic coverage for both versions before you choose.

Standard or Pro. Both start the same way.

From £1,800. Four questions, and we tell you the realistic coverage before you choose.

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The network
04

We already know who prices what.

Building the list is the slow part of this work, and it is done before your drawings arrive. Each firm has agreed to price a measured schedule at design stage and to state how long their figure stands. A cost plan is assembled from live quotes rather than from a book.

Holds run from thirty days to twelve months, depending on the trade and the firm. One supplier gives no written hold at all but has not raised a price in four years, which tells you as much. Whatever the position, it is written on the line beside the price, with the date.

Trades coveredCentral Scotland and North East England
Windows and doors
Timber frame
Cladding and rainscreen
Structural panels / SIPS
Glazing and rooflights
Roofing in progress
Insulation in progress
Structural steel with Pro
Groundworks with Pro
Heating and MVHR in progress

Pink marks a trade we can price at design stage. Most come from a named supplier. Structure and foundations come from the chartered engineer appointed under Pro, which is why they show as ranges in the standard plan. Grey marks a trade we are still building out, and those lines come through as allowances with the benchmark stated. Never as a quote.

See it on your own project.

Tell us about the project and we come back within two working days.

Cost planFrom £1,800
Cost plan ProFrom £3,900
info@arko.build
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Arko Tech Limited. 5 South Charlotte Street, Edinburgh, EH2 4AN. Contact: 0131 212 5858
Registered in Scotland. Company No. SC884278