NoneI've watched our own home here in N.Fla (1650sqftStick Built Frame 4b/2.5Ba rise since 1995 from $54k to now valued (appraisal last week for another re-fi) @ $298k on 5 acres; we've put on a new roof, upgraded A/C units, & done some BASIC landscaping...nothing more;An adjacent 7.5 acres purchased same time...raw land...1.4K per acre...then, $14.5 k value now(at least, several comps locally exceed this figure...hmmmm?)

This was a deal, not sure how I missed it, a duplex for 60k, looks like the budget would be about 5k MAX, if needs a new roof then make it 20k.

Purchase price: $110,000 Cash invested: $75,000 Sale price: $275,000 Took the existing 3 bedroom 2 bath house to a 4 bedroom 2 bath house by finishing the basement, updating the kitchen and bathrooms, installing AC, replacing roof etc.

.#3 Contact Local Contractors for Labor Pricing / Hire a GC to ConsultCall local Subcontractors and get budget pricing for common repairs on your typical rehab project.For example, call a roofer and ask what their average cost per Square of Architectural Asphalt Shingle Roofing would be on a 1,500 sf house, with a 6/12 pitch.Note: Some contractors will be reluctant to share pricing without seeing the property, but tell them you are just looking for a rough budget number you can use on future projects.You can also pay a General Contractor a consulting fee of a couple of hundred dollars (per house) to walkthrough a few properties with you and provide a detailed estimate of prices that you can use as your 'menu for future projects.#4 Compile Your Prices into a Spreadsheet or Estimating SoftwareOnce you start to get a better understanding of Labor and Material costs you will want to store this data into a spreadsheet or software that you can use to help you streamline the estimating process.The Book on Estimating Rehab Costs comes with a spreadsheet that you can use to help you populate your own database of labor pricing and material pricing.

For example, if during diligence you discover the roof needs to be replaced, your valuation should immediately adjust to account for the cost.

I noticed that there is a divot in the roof that I asked about last week, and now I noticed that there is a crack on the brick siding of the house.

If the money would just sit in your bank account until the next rental property purchase or large investment, then do what @Kevin Sobilo said and pay the HELOC down quickly since you can just rack it back up again later. 

You probably want to insure for replacement cost rather than what the insurance company determines is the depreciated value of your home or a component, such as a roof.

I knew going in that it needed extensive repairs including new roof and foundation work and probably a rewire.

If it does not, the chances that you have a significant problem are minimal.Your first remediation is to go outside to look for a slope leading toward a basement, or roof downspouts emptying very near a wall.