Welcome - I'd suggest reading this article to get an idea of how it works:https://www.biggerpockets.com/guides/ultimate-real-estate-investing-guide/introduction

I understand this 'rule' is just a guide, but nonetheless it seems extreme. 

Here are some recommendations for you:Find and connect with other BP members that are in your area: https://www.biggerpockets.com/search/usersSet up keyword alerts to be notified of the topics that interest you: http://www.biggerpockets.com/alertsRead Beginner’s Guide: http://www.biggerpockets.com/real-estate-investingCheck out BP Podcasts: https://www.biggerpockets.com/podcastWishing you the best!

Luckily I have Shelby Osborne and the team guiding me. 

I do not have direct experience in Europe, but the great thing about the calculators is that they are just a guide as to what you should include, I'm sure they are applicable to any market.

CLICK HERE for a sample guide.

Is there a rule of thumb we can use to guide us?

I rose out of poverty because I did nothing but work for 10 years and save (whilst never living on my own or having kids), then put that money into different properties totaling around 1.6 mil at the time. 

Are there any experts out there who can help guide me as to what I can do to be able to get our property fixed?

location=MA&keyword=&persist=&ajax=0State guidence on coronavirus unemployment: https://www.mass.gov/resource/information-on-unemployment-and-coronavirus-covid-19Zero-hour or furloughed eligibility: https://www.businessinsider.com/what-is-zero-hour-schedule-unemployment-benefits-2020-3Self-employed or independent contractors: https://www.thebalancecareers.com/can-i-collect-unemployment-if-i-m-self-employed-2064148Seek housing assistanceOverview on housing assistance in Mass: https://www.mass.gov/guides/a-guide-to-obtaining-housing-assistance#-rental-assistance-Retal assistance section: https://www.mass.gov/guides/a-guide-to-obtaining-housing-assistance#-rental-assistance-Framingham Housing Authority: https://framinghamhousingauthority.org/GeneralFederal stimulus package FAQ: https://www.nytimes.com/article/coronavirus-stimulus-package-questions-answers.htmlHighlights:- Payments coming to most Americans w/in 3 weeks of $1,200 (ensure your taxes are up to date to receive payment)- $600 federal unemployment for both persons receiving state unemployment benefits AND for self-employed and contract workers for up to 4 months- Federal student loans payment deferred for 6 months- Up to $100k withdrawn from IRA or 401k w/o penalty in 2020 for coronavirus hardshipsIRS page for stimulus package: https://www.irs.gov/newsroom/irs-operations-during-covid-19-mission-critical-functions-continueGeneral pandemic financial advice: https://fortune.com/2020/03/26/stimulus-package-how-to-unemployment-benefits-small-business-student-loans-self-employed-retirement-coronavirus-bill/Please use this information to your advantage the best you can; the goal is to continue our lives as normal (except while staying 6ft apart of course).