However, many people who have yet to undertake the work are discovering a shortage in supply as there is a last-minute scramble to fit the new detectors.
From February 1, all homes in Scotland will be required to have linked alarms in living rooms or the most used room, as well as spaces such as hallways and landings.
There also needs to be a heat alarm in the kitchen and a carbon monoxide alarm if people have a carbon-fuelled appliance, like a boiler, fire, heater or flue.
The new legislation follows the devastating Grenfell fire in London in 2017, and applies to all Scottish homes.
The Scottish Government estimates the cost for an average three-bedroom house which requires three smoke alarms, one heat alarm and one carbon monoxide detector will be around £220.
Its implementation has already been pushed back by a year due to the pandemic.
But opposition parties have called on the SNP Government to delay it further to give householders time to guarantee the system is fitted.
Housing Minister Shona Robson claimed in Holyrood the alarms were available for purchase and delivery for Scots who still need to install the devices.
She said: "It is local authorities who have the duty for ensuring compliance with these standards in their local area.
"They will be taking a proportionate and measured approach to compliance, taking individual circumstances into account as well as reflecting the evolving situation with the Covid-19 pandemic.
"I can be absolutely clear that there are no penalties for non-compliance and no-one will be penalised if they need more time.”
But stockists across Falkirk district are reporting empty shelves as people rush to meet the deadline of next Tuesday.
A spokesperson for WJ Electrical Supplies in Middlefield said: “We have been very busy but at the moment we are out of stock and not expecting more deliveries until next month.
"Some people were prepared well in advance but it’s human nature that many left it to January to look to install the alarms. There are also others who weren’t aware of the legislation.”
The nearby Falkirk B&Q store was reporting smoke and heat alarms currently out of stock.
While fitting the alarms is the responsibility of homeowners with social housing it falls to landlords.
Falkirk Council said four out of five of its properties had the upgraded alarms and 3000 homes still need to have them fitted.
A spokesperson said: “Our programme to install upgraded smoke and heat detectors has gone well with circa 13,500 of our properties now fully compliant with the new legislation.
“All tenants were contacted to arrange for the installation but there are a number of properties we have failed to gain access to plus we have experienced some delays due to Covid-19 restrictions.
“We will be upgrading the remaining properties as soon as possible.”
Meanwhile, a Link Group spokesperson said: “I can confirm we have been running a planned programme to meet this standard across all our areas of operation and are contacting tenants to pick up on where we haven’t been able to gain access so far for reasons including tenants isolating due to Covid, to complete this work.”