Porous asphalt is open graded and must be supported by a compatible drainage structure. Laying access and the size of the job affect contractor availability. Use the dedicated calculator to explore a guide budget for the work described below.
Estimate porous asphalt driveways from the measurements and work options below. Guide allowances are already included; a contractor’s quote is not required to use the tool.
The surface rate does not cover difficult excavation or an attenuation system.
Guide model reviewed 7 November 2026. VAT treatment varies between published guides and supplier quotes; no VAT is added automatically. Add it only where your allowances exclude it.
The selected surface guide is multiplied by the measured area. It is an early installation allowance, not a named-product quotation. Ordinary preparation must not be added twice. Existing-surface breakout, abnormal ground, engineered drainage, boundaries and highway work need their own agreed scope where excluded.
View the published guide used for the main allowance. Optional allowances are budgeting estimates and can differ from a site-specific quotation.
Use a measured specification to compare prices for your property. Ask contractors to confirm the work, preparation, materials, access, disposal and any exclusions before agreeing a price.
Porous Asphalt Driveway planned around your property
Porous asphalt is open graded and must be supported by a compatible drainage structure. Laying access and the size of the job affect contractor availability.
The surface rate does not cover difficult excavation or an attenuation system.
Porous asphalt is open graded and must be supported by a compatible drainage structure. Laying access and the size of the job affect contractor availability.
The surface rate does not cover difficult excavation or an attenuation system.
Measure the length and width of the work area in metres. Split an irregular outline into rectangles and add their areas. Where a depth or unit-count field is provided, it gives a separate quantity check; it does not decide the correct construction specification.
The selected surface guide is multiplied by the measured area. It is an early installation allowance, not a named-product quotation. Ordinary preparation must not be added twice. Existing-surface breakout, abnormal ground, engineered drainage, boundaries and highway work need their own agreed scope where excluded.
The first guide option is porous-asphalt supply and lay. Its allowance is £70–£110 for the relevant unit shown in the result. This is a published-guide starting point; it is not a price offered by a contractor on this website.
This page models porous-asphalt supply and lay. A different construction or repair method needs a separate allowance rather than an assumption that every job has the same scope.
The project controls include:
The results show the measured quantity, the selected work allowance and any separately selected items. A volume, unit count or coverage result is a quantity check, not a construction design. Where the model uses a minimum visit allowance or whole bags, the displayed total will not fall in direct proportion to a very small area.
Use the optional contingency to make a separate budget provision. Add a quoted fixed allowance only for work outside the model’s stated scope. Check the VAT basis before selecting the VAT adjustment.
Give contractors the same measurements and work description. Ask them to identify the main work, preparation, disposal, access requirements, drainage and any making-good that applies to this project. An apparent saving can simply mean that a different part of the scope has been priced.
The surface rate does not cover difficult excavation or an attenuation system. Keep the agreed specification with the quote, including any exclusions and the way changes discovered during the work will be authorised.
Examples use the specification named on each card, the calculator’s example measurements and guide allowances. Optional extras, contingency and VAT adjustment are off. Supply-only models exclude installation.
The selected surface guide is multiplied by the measured area. It is an early installation allowance, not a named-product quotation. Ordinary preparation must not be added twice. Existing-surface breakout, abnormal ground, engineered drainage, boundaries and highway work need their own agreed scope where excluded.
Measure the length and width of the work area in metres. Split an irregular outline into rectangles and add their areas. Where a depth or unit-count field is provided, it gives a separate quantity check; it does not decide the correct construction specification.
Porous asphalt is open graded and must be supported by a compatible drainage structure. Laying access and the size of the job affect contractor availability. The surface rate does not cover difficult excavation or an attenuation system.
The figures are early budgeting allowances for the work described in the selected option. The surface rate does not cover difficult excavation or an attenuation system. Ask a contractor to confirm the measured scope, access, preparation, materials and exclusions after assessing the property. The written quotation, rather than the calculator, establishes the work and the agreed price.
The result separates the main work from selected options and any additional allowance you enter. Do not add an item again if the main rate or contractor’s quote already includes it. Contingency is optional and is shown separately.
No extra VAT is added automatically. Published cost guides and supplier prices can use different VAT bases, so check the source and any written quotation. The optional VAT control adds 20% to the calculated allowances only when you select it. Leave it off when the rates or quotation already include VAT to avoid counting tax twice.
