Journal

Which costs sit outside a prefab house price?

Prefabwise Editorial Desk

A prefab house price is only one line in your project budget. To find the amount you need, add the plot, work needed to make it buildable, delivery and installation, utility connections, professional services, statutory charges and the costs of making the home ready to occupy. The exact split depends on your site and the supplier’s written scope. Treat every item as included, excluded or awaiting a priced allowance before comparing offers. [4]

Start with the offer boundary

Ask what the manufacturer’s price supplies, delivers and installs, and where that responsibility ends. A house price may exclude foundations, crane hire, access works, on-site assembly, service connections, internal completion or external finishing. Verify each item against the offer instead of assuming it is included or excluded.

Build a comparison sheet with a row for each item and columns for the quoted amount, who provides it, whether VAT is included, the quote date and any open assumptions. Mark a line “included” only when the offer says so. If the supplier gives an allowance, record what it covers and who pays if the final cost is higher. The Society of Chartered Surveyors Ireland advises an overall budget that includes build costs, utility costs, fees, charges, levies and contingency. A quantity surveyor can help estimate the required budget. [4]

Budget for the plot and site works

A plot can need work before a delivered house can be installed. Get site-specific prices for setting out, excavation, foundations, drainage, retaining structures, temporary access, storage, crane positioning and reinstatement of disturbed ground. A sloping, constrained or remote site may require different work from a straightforward site, so a generic allowance is not a substitute for a site assessment.

Check the manufacturer’s foundation design and installation requirements against the groundworks contractor’s scope. Confirm who provides the design, prepares the base, checks levels and accepts the completed foundation before delivery. Ask whether the delivery price includes transport to the plot, unloading and lifting into position. A quote that stops at the roadside leaves a different cost boundary from one that includes placement and assembly.

Price utility connections and private-side work

Electricity and water connection charges are only part of getting services to the home. As of 03.10.2026, ESB Networks lists typical charges of €3,602 for a single standard domestic connection and €4,877 for a single enhanced 16 kVA connection. The application requires site plans, location coordinates and load and connection-capacity details, so use the connection quote for your plot in the working budget. [1]

As of 03.10.2026, Uisce Éireann lists standard charges for a single domestic connection of €2,272 for water and €3,929 for wastewater, each based on connection infrastructure up to 10 metres. Water charges assume standard parameters, and requirements beyond them may incur extra charges. For wastewater, infrastructure beyond 10 metres incurs additional quotable charges, and a non-gravity pipe connection may cost more. Check the current charges and connection design for your application. [2]

Allow separately for the private-side pipework and other works in the agreed design. Uisce Éireann says the customer must complete private-side works before it or an authorised agent makes the final connection to the public water or wastewater network. Ask the utility and contractors to identify their work boundaries and price any required site works. Check whether public wastewater service is available at the plot and what connection or other wastewater arrangements it needs. [3]

Add professional services and statutory costs

List the services needed for your project rather than applying a guessed fee percentage. Depending on the procurement route and what the supplier includes, you may need an architect or building surveyor, engineer, quantity surveyor, project manager, planning support and compliance or inspection services. Ask each professional for a written fee proposal that names the stages and deliverables. The Society of Chartered Surveyors Ireland says these professionals may be needed at different stages and recommends including fees in the overall budget. [4]

Add planning and local authority charges, building control or certification costs, legal and finance costs, and any applicable development contributions as separate lines to verify for your project. Requirements vary by project and location, so check the planning conditions, local authority requirements and your project team’s responsibilities. Do not assume the manufacturer’s price covers these services or fees unless its offer explicitly says so. [4]

Allow for completion and moving in

A delivered house may still need work before it is ready to occupy. Check the offer for utility activation, heating and ventilation commissioning, final electrical certification, internal finishes, appliances, steps or paths, driveway, fencing and landscaping. Include inspections, cleaning, temporary accommodation or storage, insurance during the works, and mortgage interest or other finance costs where they apply to your project. [4]

Keep contingency as its own budget line rather than hiding it inside an unexplained allowance. The Society of Chartered Surveyors Ireland recommends including a contingency sum and says a quantity surveyor can help estimate the required budget. Ask for help where the project is complex or the remaining estimates are uncertain. [4]

Questions to send before accepting a quote

Ask the manufacturer: “Please list what your price supplies, delivers and installs, and identify the exact point where your work ends. Which foundations, site works, lifting, utility connections, private-side services, fees, finishing and certification are excluded? Which amounts are fixed prices, which are allowances, and what assumptions could change them?” Then request dated written prices for the remaining work from the relevant professionals, utilities and contractors. Add those figures to the same scope-based budget before deciding whether the house price fits your total budget. [1] [2] [3] [4]

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