How to compare a shell offer with a completed home
Compare the shell offer with a completed-home offer by adding the cost of every excluded task to the shell price, using written quotes for your site and chosen finish level. Include delivery, installation, site works and connections where they fall outside either offer. Until suppliers confirm the same scope and cost boundary, the price gap is not a saving you can rely on. [2] [3]
- A shell price and a completed-home price are comparable only after you define the same finish level and cost boundary for both. [2] [3]
- Ask local tradespeople for written, itemised quotes for the work excluded from the shell offer; do not treat an allowance or estimate as a confirmed price. [2] [3]
- BIOBUILDS says its turnkey package includes interior finishes and installed systems, but excludes kitchen furniture and appliances; the accepted offer and contract control the buyer’s actual scope. [1]
Start with what each offer leaves out
Write down the outcome you expect from both offers, such as a home with finished floors, working bathroom fixtures and tested heating and ventilation. Then mark each item included, excluded, provisional or unclear in each supplier’s documents. A label such as “shell” or “turnkey” does not define the work. Check the accepted offer and contract for your own specification. [2] [3]
Build a priced completion list
For every item marked excluded or unclear, identify who will supply it and request a written price for the work your shell offer leaves to you. Depending on the offer, the list may include interior finishes, electrical and plumbing completion, heating or ventilation equipment, kitchen supply, delivery, assembly, foundations, site works and utility connections. These are prompts to check against the actual documents, not assumed exclusions. Keep allowances separate from firm quotes and record whether tax, materials, labour and follow-on work are included. [2] [3]
Ask for like-for-like local quotes
Send each local contractor the same drawings, specification, site information and completion list. Ask for an itemised written quote that states the work, materials, price validity, tax treatment, exclusions and any conditions that could change the total. Ireland’s Competition and Consumer Protection Commission advises securing written quotes from multiple contractors and getting clear written details of the agreed price, work and payment structure. Citizens Advice in Wales recommends written quotes from at least three traders and distinguishes a fixed quote from an estimate; that guidance is specific to Wales, but the distinction is useful when labelling your comparison. [2] [3]
Compare the completed totals and the remaining risk
Use a simple calculation for each offer: supplier price plus separately quoted completion work plus delivery, site and connection costs not already included. Add a separate line for costs that still lack a quote; do not fill gaps with assumed labour savings or a made-up contingency. Compare the totals only when the offers cover the same home, finish level, site assumptions and tax basis, and each figure is still within its stated validity date. Record the offer or quote date and source document beside every line. If one supplier cannot price an item yet, show it as unknown and ask what information is needed to confirm it. [2] [3]
Get the scope into the contract
Before choosing, ask each supplier to confirm the final inclusion list, exclusions, allowances, responsibility for each remaining task, payment stages and any dependencies on site preparation. The CCPC notes that written records help show what was agreed if a dispute arises; contracts may also be formed through quotations, emails or conduct, so keep those records together. A lower headline price becomes meaningful only when you can see what the finished home will cost and who is responsible for delivering it. [2]
Send both suppliers the same completion list and ask: “Which items are included in this offer, which remain my responsibility, and can you price each remaining item for my site in a written, itemised quote?” Compare the resulting totals and leave every unpriced item visibly unresolved. [2] [3]