Get a budget range

The calculator estimates the construction cost range based on property type, age, scope of works, specification tier, and structural complexity. It excludes VAT. It excludes professional fees paid outside Myrmex, including architect, structural engineer, and planning consultant. It excludes client-side furniture and FF&E. Statutory fees beyond what the calculator flags are also excluded.

No. The calculator returns an indicative range, not a binding figure. The binding number is the cost plan locked at the Pre-Construction Services Agreement (PCSA) stage. The PCSA is a paid four-week pre-construction process where every line item is priced and signed before the main construction contract is entered.

Residential properties between 25m² and 1,000m². Above 600m², the calculator advises contacting Myrmex directly. Property types: period house, period flat, new-build house, new-build flat. Listed buildings supported, including Grade II, Grade II*, and Grade I. Location input is by London Underground zone: Zone 1, Zone 2, Zone 3, or Zone 4 to 6. The calculator scope is wider than the Myrmex service area by design.

The calculator is a pre-engagement indicator. It runs on twelve panels of structured input and returns a low, mid, and high range. The PCSA is a paid four-week process where every line item is priced and signed before the main construction contract. The cost plan locked at the end of the PCSA is the binding number. The calculator narrows the gap between indicative and binding; it does not close it.

Two options. The first is the full email breakdown: enter first name and email, and the calculator sends every line item, the programme timeline, and procurement flags to your inbox. A reference number is issued (format MG-XXXXXX). The second is a fifteen-minute call via Calendly. Neither carries an obligation. The calculator does not require an email to return the indicative range; the breakdown is opt-in.

The construction cost is calculable. An indicative range can be modelled from GIA, scope, and specification tier. The number is rarely published before engagement. The client receives it after entering the conversation, not before. Myrmex previously ran a different company for two years and did not publish a calculator. The calculator does not know the building; the PCSA is where the building gets known. Publishing it changes the timing: the client arrives with a number rather than waiting for one.