Attic conversion budget: handling structural surprises

An attic conversion can turn up surprises in the existing framing and behind the roof: weak joists, old wiring, a duct in the way. The sheet keeps planned scope apart from change orders and shows how much of the contingency pool the overruns have used.

General information only, not financial, construction or legal advice. Contingency, holdback and payment-split percentages are your own inputs, and payment and deposit rules vary by contract and by state or province; check yours. Names and numbers in the example are invented.

What changes for this kind of project

In this example the framing crew handles the joists, the insulation and the stairs, so three lines share a contractor, and the Contractors tab adds that crew's approved change orders into one current contract.

In this example two surprises are approved: sistered joists on the framing line and a reinforced floor opening on the stairs line. Both lines now sit above their line budget and draw on the contingency pool. The panel upgrade is only Proposed, so it stays out of Committed until you mark it Approved.

A worked example: Attic conversion, 350 sq ft

Invented numbers, to show the shape. Settings on Start Here: contingency 18% (an example value you set), total project budget $40,700.

The contingency pool is $7,326 ($40,700 x 18%). That leaves $33,374 to share out as line budgets. The lines below add up to $33,350, so $24 is unallocated.

Change orders on the Change Orders tab. Only Approved rows move into Committed:

What the summary shows

• Committed: $30,550. Paid: $11,750. Unpaid commitment: $18,800.
• Contingency used: $1,950, what each line's committed total goes above its line budget, added up. Contingency left now: $5,376.
• Pending exposure (Proposed change orders): $650. Contingency left if every proposed change order were approved: $4,726.

Where each piece goes in the workbook

1. Start Here: Type the total project budget, which includes the contingency pool, the contingency percentage and the three contractors with their trades. The percentage is an example value you overtype; the pool and Unallocated are worked out for you.
2. Budget: One row per scope line, L01 to L08, with room, category, contractor, line budget and accepted quote. Drywall has no quote yet, so its row reads Not committed and counts as zero in Committed until you type one.
3. Change Orders: Log the sistered joists and the stair opening reinforcement with reason Unforeseen and status Approved. Log the panel upgrade as Homeowner change, status Proposed. Only Approved rows move into Committed on the Budget tab.
4. Rooms & Summary: Every line uses the Attic room, so the room table has one row, and the category table splits the same figures by category. Read Contingency used and Contingency left now in the contingency summary there.

Two formulas worth a cell of their own

• Committed for one room: =SUMIFS(Budget!$K$6:$K$65,Budget!$B$6:$B$65,"Attic") returns $30,550 on this example.
• Contingency used, the sum of the Overrun now column: =SUM(Budget!$S$6:$S$65) returns $1,950.

Four tracking tips

1. Give the stairs their own line, apart from the joists. The reinforced floor opening then lands as a change order on the stairs line, and that row flags Over budget on its own instead of hiding inside one large framing number.
2. The panel upgrade is Proposed, so Contingency left if all pending approved is lower than Contingency left now. Compare the two before you answer the electrician; the electrical line is already above its line budget on its quote alone.
3. If you pay the framing crew by percent milestones on the Cash Schedule, those percentages use the original quote. Add the sistered joists and the stair opening as Fixed $ rows, so the schedule includes them.
4. Drywall has no accepted quote, so it reads Not committed and adds nothing to Committed. The Forecast column carries its line budget instead, so the plan still holds a place for it until you type a quote.

Questions

Where do I log a structural engineer's fee for the joists?

Add a scope line in the Design & planning category with the fee as its budget and its accepted quote, and leave Contractor empty if you pay the engineer directly. It then gets its own row and flag instead of being absorbed by the framing line.

What if the HVAC duct turns out not to reach the attic?

Log the extra work as a change order on the HVAC line with the contractor's price and status Proposed. It counts as pending exposure only. When you agree to it, change the status to Approved and the amount joins Committed on that line.

Related renovation guides

• Renovation budget spreadsheet: track committed vs paid
• Renovation change order tracker: a spreadsheet for homeowners
• Renovation contingency tracker: how much contingency is left

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