I used to be a green contractor and was a whole house diagnostic engineer (before HERS rating was all the rage) and completed millions of square foot of conservation measures.

It would have cost me about 150 to do it on yellow letters, so I am measuring my costs including materials, labor time, and a time factor.

He even measured the railing on the balcony and discovered it was not up to code.

When it comes to buying and working with sellers, you always have to measure the seller.

Here are the measurments for the rooms and below is a crude depiction of the layout for each floor.-- (Excel was not meant for this purpose).BR1-  8x12BR2 -8x12Bath appox -10x5- with small vanity 24", 60"x30" tub and toiletLiving Room-10x13Kitchen-8x10-  about 10 LF of cabinets, about 22 sqft of counter tops.I have run some numbers and have a relatively decent idea of what I believe materials would cost per unit (around 8K), but the labor is the wildcard right now. 

So it's definitely not a market multifamily investors target.Very stable market though with high demand. 10 of the 20 richest counties as measured by median income are here in the DC area.

How do you measure your investment results?  

Nicholas,Before replacing a toilet, measure the rough in or make sure your plumber measures before buying.To measure accurately, measure from the wall–NOT the molding–to the bolt caps.It seems weird that you have 9 inches to the center of the flange.Why not just return the wrong toilet and buy a 10 ".I would avoid cutting into the wall, any time you jury rig something it will decrease the value of your house.

You answered your own question in the post- "Free up your line of credit for more potential property purchases"  I would measure how long it would take to purchase another property & create more cash flow if you don't refinance versus how long it will take to purchase another property & create more cash flow (& equity) if you do refinance.  

Now a measurable percentage of those people are deciding to stay.