The advisor says.

'Even though Helen has stated that she can tolerate some risk, a four-year time-horizon until she buys a house makes investing her savings earmarked for the down payment in market-based securities such as stocks or bonds unadvisable, Ms. Ulmer says. “The risk of a market decrease over a four-year time horizon could jeopardize her principal and the goal of a 20-per-cent down payment by 2021.”'

Then the advisor says to put her down payment money into a savings account at 1%.

Yes, if interest rates go up the value of a bond drops, but only if you are trying to sell it before it matures.  A quick check on my broker's site shows a number of  'A' and higher rated bonds that mature in 2021 that are paying just under 2%.

Why not buy these and double your return?  The value of the bond does not drop if you hold until maturity, and you get an very safe return double the return on a savings account.

Plus there are other options that pay 2% or better that are CDIC insured.