"We would regard changes to the core principals as desirable but not really critical. We're hearing there are other coalition partners who might have an appetite to consider other parts of the act, but not the core principals," he said.
Townsend identified areas where he said good RMA reform progress could be made:
•Incorporating what he said was the successful Housing Accords and Special Housing Area (Hasha) legislation into the RMA to permanently make provisions for the potential to fast-track housing development. Townsend hailed that initiative between local authorities and the Government to get many areas rezoned to allow speedy housing development but said the legislation had a finite period and would expire, so needed to be a permanent part of the RMA.
"There's an awful lot of good stuff that has been happening with Hasha and a lot of lessons that have come out of it."
•Using what's been learned from submissions to Auckland Council's proposed unitary plan and Christchurch's district plan. Townsend said this included the suggestion for limits on the scope of district plans.
"A lot has come out of those two in terms of the broad policies - maybe they're too broad," he said.
•Speeding up consents for new housing developments to resolve the severe shortage, particularly in Auckland and Christchurch.
One RMA expert said if the entire reforming of the act was as big as a telephone book, the part National had lost was probably equivalent to the size of the first page.
But Jordan Williams, executive director of lobby group the Taxpayers' Union, was left fuming by the Northland result.
"As a result of the byelection, meaningful RMA reform will be extremely difficult which means that for younger people and my generation, the enormous hidden regulatory tax that is the RMA is unlikely to be tackled," Williams said.
"If National was able to deliver meaningful changes that allowed more houses to be built and prevented councils strangling supply, that would dwarf any tax cut that they'll realistically be able to provide.
"The cost of the RMA is an enormous hidden tax and one of the main reasons why housing is so unaffordable due to the restrictions on the supply."