But here’s what I’ve learned in writing a blog over the last 9 months: 1) it takes me much longer than I would have anticipated. Between writing, editing, posting, and then correcting the sloppy format I always seem to end up with, it takes me a couple of hours to get one of these short pieces up. 2) When I’m traveling, if I don’t post within a day or two of wherever I was, I absolutely forget the nuances of whatever it was I found interesting or new or challenging. So somehow I have to find the self discipline (never one of my strong suits) to get these missives written quickly. I’ll work on that.In the meantime, as many of you have heard me say over the years, what I really am is not an economic development consultant, or preservationist, or real estate consultant or economist, but a list maker. I tend to think in lists.

So the first blog of 2009 is one of my lists — 20 things we’ve learned about historic preservation.

1. Not every historic building can be adapted for every use, but the vast majority of quality historic buildings can be adapted to the vast majority of uses.

2. You can nearly always build something cheaper than you can do a complete renovation; but if quality is part of the equation, historic preservation is a cost competitive alternative.

3. The more similar the adaptive reuse of the historic building is to the original use, the more cost effective the rehabilitation will be.

4. The cost competitiveness of rehabilitation versus new construction is distorted when the costs of demolition and disposal are not included in the new construction cost estimates.

5. The remaining economic life of a quality rehabilitated historic building is not measurably different than the remaining economic life of a quality new building.

6. Rehabilitation will be more labor intensive (60/40) then new construction (50/50) which results, dollar for dollar, in a significantly greater local economic impact from rehabilitation project.

7. There has never been a major preservation success story where, before the project began, some building inspector, architect or structural engineer didn’t claim, “This building has to come down – it’s on the verge of collapse.” Rarely, in fact, is that true.

8. Architects, contractors, trades and structural engineers who are experienced in rehabilitation projects will be much more creative in addressing problems and cost effective in construction than will those professionals who deal primarily with new construction.

9. It is nearly always a mistake, both functionally and economically, to try to force the interior design dejure into a historic building. It is neither “form follows function” nor “function follows form” but accommodating the necessary functions creatively into the existing form.

10. 90% of historic preservation projects fit seamlessly into the existing physical context. Maybe 20% of large new buildings do.

11. Items likely to cost more in total rehabilitation projects on a component-pricing basis are: interior construction, conveying, mechanical, general conditions. Items likely to cost less include: foundation, superstructure, exterior, roof structure. Items likely to be equivalent: substructure, electrical, architect.

12. Projects not requiring total renovation will be much more cost effective than even moderate quality new construction.

13. “Functional obsolescence” in historic buildings is far more often a conclusion drawn from unchallenged conventional wisdom than from reality and usually is much more indicative of designers either not experienced in rehabilitation projects or lacking in imagination.

14. Technological innovations are steadily increasing the comparability of rehabilitation to new construction in systems and environmental response. At the same time historic buildings were designed to accommodate the local environment and there are important lessons to be learned from them.

15. As the time horizon for building use and ownership lengthens the relative advantage of rehabilitated historic buildings increases. Therefore institutional ownership (which has a long-term investment horizon) of rehabilitated historic buildings often makes more relative sense than it does for those with a short-term investment perspective.

16. The cost effectiveness of historic preservation as part of an urban revitalization strategy far surpasses the “tear down and build up” urban renewal mistakes of the past.

17. Historic preservation is a core element of an environmentally conscious, stewardship minded public policy.

18. There are uncertainties with historic preservation and the unexpected will happen – things will go wrong. Experienced architects and contractors understand, however, that while some things will go wrong, everything won’t go wrong.

19. Historic preservation provides connection and continuity to the local culture.

20. We know what the most expensive mistakes are.