The building's sensible heat load will be unchanged so the existing boiler will be sufficient.

My expenses have largely remained unchanged.

However, between when I sold it in 1999 until late 2002, the value was unchanged.

So your cash flow is typically going to have zero appreciation.   10 years from now when the rent is virtually unchanged (historically rent appreciation no better than appreciation but property has aged so your particular property would be fortunate to have had any rent appreciation) but maintenance and cap expense has increase at least at rate of inflation.  

If the pressure is unchanged, you're good.Now, if you have leak, you can use the soapy water method to track it down

The basics of a good real estate investment seem unchanged at the core: location, population growth, neighborhood demographics, supply and demand, surrounding amenities, etc.

Taxes, even for those high earners, are unchanged on income below those amounts.

I inform the buyer that regardless of the inspection results the purchase price will remain unchanged.

Highlights: Single-family home sales were basically unchanged with a total of 7,696 units sold;On a year-to-date basis, single-family home sales are up 2.7 percent;Total property sales fell 0.9 percent to 9,139 units;Total dollar volume declined 1.7 percent to $2.6 billion;At $230,538, the single-family home median price rose 2.5 percent to a record high;The single-family home average price declined 0.8 percent to the second highest level of all time, $300,178 (the highest was $302,599 in June 2015);Single-family homes months of inventory climbed to a 3.7-months supply versus 3.2 months a year earlier;Townhome/condominium sales fell 5.8 percent with the average price down 2.4 percent to $197,937 and the median price up 2.1 percent to $164,450;Leases of single-family homes were up 4.8 percent with rents up slightly to $1,883;Leases of townhomes/condominiums soared 12.9 percent with rents down 5.6 percent to $1,658.http://www.har.com/content/newsroom

So that is not ideal and unchangeable.