DIY or Hire a Pro? A Cost‑Time Budget Test

Pick your model—then run the same Cost‑Time Budget Test for every project. This keeps “Should we do it ourselves?” from turning into resentment, second‑guessing, or silent scorekeeping.

Pick your model

Choose the money model that fits your relationship right now. More than one can be fair.

Proportional (by net income)
Best when incomes differ and you want the joint life to feel equally affordable.
Equal split with a comfort cap
Best when you value simplicity, and you want a built‑in safety rail for bigger costs.
Role‑based (who wants it, who leads it)
Best when one person cares more about the outcome, or one person has the skills/time to lead.

Once you pick, write it down, decide the roles, and only revisit if something materially changes (income, living situation, health, workload, or the scope of the project).

The Cost‑Time Budget Test (DIY vs Pro)

Use this test in one sitting before you buy anything or book anyone.

Step 1: Name the project type

Joint essential: safety, structural, water, heat, legal compliance, “we can’t live like this.”
Joint nice‑to‑have: comfort, aesthetics, upgrades.
Personal treat: primarily one person’s preference (even if it’s in a shared space).

House rule we like: personal treats are paid personally; joint essentials are shared.

Step 2: Set two budgets (money and time)

Money and time both need a ceiling, or DIY becomes a hidden invoice.

Money budget: set as a % of combined take‑home (or of the payer’s take‑home if it’s a personal treat).
Time budget: set as time blocks you can realistically give without stealing rest or relationship bandwidth.

Then decide: What happens if we exceed either budget? Our default: switch to “hire a pro” when a budget is breached—no guilt, no lecturing.

Step 3: Add the “stress multiplier”

Ask each person for a quick rating:

Stress if DIY goes wrong (low/medium/high)
Stress if we pay for help (low/medium/high)

If either person says “high” on DIY going wrong for a joint essential, we treat that as a strong signal to hire a pro.

Step 4: Decide who owns outcomes (roles, not policing)

Pick roles so nobody becomes the unpaid project manager by accident.

Project Lead: decides plan and timeline, keeps decisions moving.
Finance Buddy: tracks spending vs the % budget, handles quotes/invoices.
Quality Check: reviews final result against a simple checklist.

One person can hold two roles, but nobody should hold all three unless it’s their personal treat.

Copy‑paste rules (adapt as you like)

Rule set A: Proportional split + shared essentials

For joint essentials, we split costs proportional to net income (e.g., 60/40).
For joint nice-to-haves, we use the same split but require both to say “yes.”
Personal treats are paid by the person who wants them.
If either the money budget (% of take-home) or time budget is exceeded, we pause and choose: downgrade scope or hire a pro.

Rule set B: Equal split with a comfort cap

We split joint costs 50/50 up to a comfort cap (% of combined take-home).
Above the cap, we decide together: postpone, reduce scope, or switch to proportional splitting for the remainder.
Personal treats are personal spending and don’t need approval if they don’t create shared work.

Rule set C: Role‑based (“You want it, you lead it”)

If one of us wants the project more, that person is Project Lead.
Joint essentials are shared by our chosen split model.
Joint nice-to-haves require a clear plan + time budget; otherwise we hire a pro.
If the Lead chooses DIY, the Lead owns coordination and cleanup; the other person can opt out without punishment.

Fairness options (pick one, not all)

When DIY creates uneven labor, choose one fairness option so it doesn’t linger.

Labor counts as contribution: DIY hours reduce what that person pays for joint costs (agreed ratio per time block).
Labor is a gift: DIY time is freely given, but only if the giver explicitly offers and can stop without backlash.
Buy back time: if one person is overloaded, the default is to hire help using the joint budget (within the % cap).

Conversation prompts (quick, non‑dramatic)

Use these to keep it practical:

“Is this a joint essential, joint nice‑to‑have, or a personal treat?”
“What’s our money cap as a % of take‑home—and what’s the time cap?”
“What would ‘done’ look like, and what’s ‘good enough’?”
“If it takes twice as long, what do we do—simplify or hire?”
“Who is Project Lead, and what decisions can they make without checking in?”

If this feels hard, start here

Default rule: Joint essentials are shared proportional to net income; personal treats are personal.
We set a money cap (% of take-home) and a time cap (time blocks). If either cap is exceeded, we hire a pro.
We assign roles: Lead, Finance Buddy, Quality Check—so effort is visible without policing.